Kurangngerti nihh ! kan rumus sinus itu A/sin A dan B/sin B. bagaimana penyelesaiannya kalau yang di cari itu A, sin A, B, sin B.. maksudnya rumusnya bagaimana seperti A = sin A. B/ sin B.. rumusnya saja. Question from @zulkifly99 - Sekolah Menengah Atas - Matematika
Sina - b is one of the important trigonometric identities used in trigonometry, also called sina - b compound angle formula. Sin a - b identity is used in finding the value of the sine trigonometric function for the difference of given angles, say 'a' and 'b'. The expansion of sin a - b can be applied to represent the sine of a compound anglein form of a difference of two angles in terms of sine and cosine trigonometric functions. Let us understand the sina - b identity and its proof in detail in the upcoming sections. 1. What is Sina - b Identity in Trigonometry? 2. Sina - b Compound Angle Formula 3. Proof of Sina - b Formula 4. How to Apply Sina - b? 5. FAQs on Sina - b What is Sina - b Identity in Trigonometry? Sina - b is the trigonometry identity for the compound angle that is given in the form of the difference of two angles. It is applied when the angle for which the value of the sine function is to be calculated is given in the form of compound angle for the difference of two angles. Here, the angle a - b represents the compound angle. Sina - b Compound Angle Formula Sina - b formula is also called the difference formula in trigonometry. The sina - b formula for the compound anglea - b can be given as, sin a - b = sin a cos b - cos a sin b, where a and b are the measures of any two angles. Proof of Sina - b Formula The expansion of sina - b formula can be proved geometrically. To give the stepwise derivation of the formula for the sine trigonometric function of the difference of two angles geometrically, let us initially assume that 'a', 'b', and a - b are positive acute angles, such that a > b. In general, sina - b formula is true for any positive or negative value of a and b. To prove sin a - b = sin a cos b - cos a sin b Construction Let OX be a rotating line. Rotate it about O in the anti-clockwise direction to form the rays OY and OZ such that ∠XOZ = a and ∠YOZ = b. Then ∠XOY = a - b. Take a point P on the ray OY, and draw perpendiculars PQ and PR to OX and OZ respectively. Again, draw perpendiculars RS and RT from R upon OX and PQ respectively. Proof We will see how we have written ∠TPR = a in the above figure. From the right triangle OPQ, ∠OPQ = 180 - 90 + a - b = 90 - a + b; From the right triangle OPR, ∠OPR = 180 - 90 + b = 90 - b Now, from the figure, ∠OPQ, ∠OPR, and ∠TPR are the angles at a point on a straight line and hence they add up to 180 degrees. ∠OPQ + ∠OPR + ∠TPR = 180 90 - a + b + 90 - b + ∠TPR = 180 180 - a + ∠TPR = 180 ∠TPR = a Now, from the right-angled triangle PQO we get, sin a - b = PQ/OP = QT-TP/OP = QT/OP - TP/OP = RS/OP - TP/OP = RS/OR ∙ OR/OP - TP/PR ∙ PR/OP = sin a cos b - cos ∠TPR sin b = sin a cos b - cos a sin b, since we know, ∠TPR = a Therefore, sin a - b = sin a cos b - cos a sin b. How to Apply Sina - b? In trigonometry, the sina - b expansion can be used to calculate the sine trigonometric function value for angles that can be represented as the difference of standard angles. We can follow the below-given steps to learn to apply sina - b identity. Let us evaluate sin60º - 30º to understand this better. Step 1 Compare the sina - b expression with the given expression to identify the angles 'a' and 'b'. Here, a = 60º and b = 30º. Step 2 We know, sin a - b = sin a cos b - cos a sin b. ⇒ sin60º - 30º = sin 60ºcos 30º - sin 30ºcos 60º Since, sin 30º = 1/2, sin 60º = √3/2, cos 30º = √3/2, cos 60º = 1/2 ⇒ sin60º - 30º = √3/2√3/2 - 1/21/2 = 3/4 - 1/4 = 2/4 = 1/2 Also, we know that sin60º - 30º = sin 30º = 1/2. Therefore the result is verified. ☛Related Topics on sina-b Here are some topics that you might be interested in while reading about sin a - b. Trigonometric Chart Trigonometric Functions sin cos tan Law of Sines Let us have a look a few solved examples for a better understanding of the concept of sina - b formula. FAQs on Sin a - b What is Sin a - b? There are many compound angle identities in Trigonometry. sina - b is one of the important trigonometric identities also called sine difference formula. Sina - b can be given as, sin a - b = sin a cos b - cos a sin b, where 'a'and 'b' are angles. What is the Formula of Sin a - b? The sina - b formula is used to express the sin compound angle formulae in terms of values of sin and cosine trig functions of individual angles. Sina - b formula in trigonometry is given as, sin a - b = sin a cos b - cos a sin b. What is Expansion of Sin a - b The expansion of sina - b is given as, sin a - b = sin a cos b - cos a sin b, where, a and b are the measures of angles. How to Prove Sin a - b Formula? The proof of sina - b formula can be given using the geometrical construction method. We initially assume that 'a', 'b', and a - b are positive acute angles, such that a > b. Click here to understand the stepwise method to derive sina - b formula. What are the Applications of Sina - b Formula? Sina - b can be used to find the value of sine function for angles that can be represented as the difference of simpler or standard angles. Thus, this formula helps in making the deduction of values of trig functions easier. It can also be applied while deducing the formulas of expansion of other double and multiple angle formulas. How to Find the Value of Sin 15º Using Sina - b Identity. The value of sin 15º using a - b identity can be calculated by first writing it as sin[45º - 30º] and then applying sina - b identity. ⇒sin[45º - 30º] = sin 45ºcos30º - sin30ºcos 45º = √3/2√2 - 1/2√2 = √3 - 1/2√2 = √6 - √2/4. How to Find Sina - b + c Using Sina - b? We can express sina - b + c as sina - b + c and expand using sina + b formula as, sina - b + c = sina - bcos c + sin ccosa - b = cos csin a cos b - cos a sin b + sin ccos a cos b + sin a sin b = sin a cos b cos c - cos a sin b cos c + cos a cos b sin c + sin a sin b sin c. Pelajaran Soal & Rumus Persamaan Trigonometri Kalau kebetulan kamu ingin belajar lebih tentang persamaan trigonometri, kamu bisa menyimak video pembahasannya yang ada di sini. Setelahnya, kamu bisa mengerjakan kuis berupa latihan soal untuk mengasah kemampuan belajarmu.Sin A - Sin B is an important trigonometric identity in trigonometry. It is used to find the difference of values of sine function for angles A and B. It is one of the difference to product formulas used to represent the difference of sine function for angles A and B into their product form. The result for Sin A - Sin B is given as 2 cos ½ A + B sin ½ A - B. Let us understand the Sin A - Sin B formula and its proof in detail using solved examples. What is Sin A - Sin B Identity in Trigonometry? The trigonometric identity Sin A - Sin B is used to represent the difference of sine of angles A and B, Sin A - Sin B in the product form with the help of the compound angles A + B and A - B. Let us study the Sin A - Sin B formula in detail in the following sections. Sin A - Sin B Difference to Product Formula The Sin A - Sin B difference to product formula in trigonometry for angles A and B is given as, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B Here, A and B are angles, and A + B and A - B are their compound angles. Proof of Sin A - Sin B Formula We can give the proof of Sin A - Sin B formula using the expansion of sinA + B and sinA - B formula. As we stated in the previous section, we write Sin A - Sin B = 2 cos ½ A + B sin ½ A - B. Let us assume two compound angles A and B, given as A = X + Y and B = X - Y, ⇒ Solving, we get, X = A + B/2 and Y = A - B/2 We know, sinX + Y = sin X cos Y + sin Y cos X sinX - Y = sin X cos Y - sin Y cos X sinX + Y - sinX - Y = 2 sin Y cos X ⇒ sin A - sin B = 2 sin ½ A - B cos ½ A + B ⇒ sin A - sin B = 2 cos ½ A + B sin ½ A - B Hence, proved. How to Apply Sin A - Sin B? Sin A - Sin B trigonometric formula can be applied as a difference to the product identity to make the calculations easier when it is difficult to calculate the sine of the given angles. Let us understand its application using an example of sin 60º - sin 30º. We will solve the value of the given expression by 2 methods, using the formula and by directly applying the values, and compare the results. Have a look at the below-given steps. Compare the angles A and B with the given expression, sin 60º - sin 30º. Here, A = 60º, B = 30º. Solving using the expansion of the formula Sin A - Sin B, given as, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B, we get, Sin 60º - Sin 30º = 2 cos ½ 60º + 30º sin ½ 60º - 30º = 2 cos 45º sin 15º = 2 1/√2 √3 - 1/2√2 = √3 - 1/2. Also, we know that Sin 60º - Sin 30º = √3/2 - 1/2 = √3 - 1/2. Hence, the result is verified. ☛ Topics Related to Sin A - Sin B Trigonometric Chart sin cos tan Law of Sines Law of Cosines Trigonometric Functions FAQs on Sin A - Sin B What is Sin A - Sin B in Trigonometry? Sin A - Sin B is an identity or trigonometric formula, used in representing the difference of sine of angles A and B, Sin A - Sin B in the product form using the compound angles A + B and A - B. Here, A and B are angles. How to Use Sin A - Sin B Formula? To use Sin A - Sin B formula in a given expression, compare the expansion, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B with given expression and substitute the values of angles A and B. What is the Formula of Sin A - Sin B? Sin A - Sin B formula, for two angles A and B, can be given as, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B. Here, A + B and A - B are compound angles. What is the Expansion of Sin A - Sin B in Trigonometry? The expansion of Sin A - Sin B formula is given as, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B, where A and B are any given angles. How to Prove the Expansion of Sin A - Sin B Formula? The expansion of Sin A - Sin B, given as Sin A - Sin B = 2 cos ½ A + B sin ½ A - B, can be proved using the 2 sin Y cos X product identity in trigonometry. Click here to check the detailed proof of the formula. What is the Application of Sin A - Sin B Formula? Sin A - Sin B formula can be applied to represent the difference of sine of angles A and B in the product form of sine of A - B and cosine of A + B, using the formula, Sin A - Sin B = 2 cos ½ A + B sin ½ A - B.
Rumusuntuk sin(a+b) dan sin(a-b) DRAFT. a year ago. by dionmathix_12798. Played 37 times. 0. 10th - 12th grade . Mathematics. 56% average accuracy. 0. Save. Edit. Edit. Print; Share; Edit; Delete; Host a game. Live Game Live. Homework. Solo Practice. Practice. Play. Share practice link. Finish Editing. This quiz is incomplete! To play this The Law of Sines or Sine Rule is very useful for solving triangles a sin A = b sin B = c sin C It works for any triangle a, b and c are sides. A, B and C are angles. Side a faces angle A, side b faces angle B and side c faces angle C. And it says that When we divide side a by the sine of angle A it is equal to side b divided by the sine of angle B, and also equal to side c divided by the sine of angle C Sure ... ? Well, let's do the calculations for a triangle I prepared earlier a sin A = 8 sin = 8 = b sin B = 5 sin = 5 = c sin C = 9 sin = 9 = The answers are almost the same! They would be exactly the same if we used perfect accuracy. So now you can see that a sin A = b sin B = c sin C Is This Magic? Not really, look at this general triangle and imagine it is two right-angled triangles sharing the side h The sine of an angle is the opposite divided by the hypotenuse, so a sinB and b sinA both equal h, so we get a sinB = b sinA Which can be rearranged to a sin A = b sin B We can follow similar steps to include c/sinC How Do We Use It? Let us see an example Example Calculate side "c" Law of Sinesa/sin A = b/sin B = c/sin C Put in the values we knowa/sin A = 7/sin35° = c/sin105° Ignore a/sin A not useful to us7/sin35° = c/sin105° Now we use our algebra skills to rearrange and solve Swap sidesc/sin105° = 7/sin35° Multiply both sides by sin105°c = 7 / sin35° × sin105° Calculatec = 7 / × c = to 1 decimal place Finding an Unknown Angle In the previous example we found an unknown side ... ... but we can also use the Law of Sines to find an unknown angle. In this case it is best to turn the fractions upside down sin A/a instead of a/sin A, etc sin A a = sin B b = sin C c Example Calculate angle B Start withsin A / a = sin B / b = sin C / c Put in the values we knowsin A / a = sin B / = sin63° / Ignore "sin A / a"sin B / = sin63° / Multiply both sides by B = sin63°/ × Calculatesin B = Inverse SineB = sin−1 B = Sometimes There Are Two Answers ! There is one very tricky thing we have to look out for Two possible answers. Imagine we know angle A, and sides a and b. We can swing side a to left or right and come up with two possible results a small triangle and a much wider triangle Both answers are right! This only happens in the "Two Sides and an Angle not between" case, and even then not always, but we have to watch out for it. Just think "could I swing that side the other way to also make a correct answer?" Example Calculate angle R The first thing to notice is that this triangle has different labels PQR instead of ABC. But that's OK. We just use P,Q and R instead of A, B and C in The Law of Sines. Start withsin R / r = sin Q / q Put in the values we knowsin R / 41 = sin39°/28 Multiply both sides by 41sin R = sin39°/28 × 41 Calculatesin R = Inverse SineR = sin−1 R = But wait! There's another angle that also has a sine equal to The calculator won't tell you this but sin is also equal to So, how do we discover the value Easy ... take away from 180°, like this 180° − = So there are two possible answers for R and Both are possible! Each one has the 39° angle, and sides of 41 and 28. So, always check to see whether the alternative answer makes sense. ... sometimes it will like above and there are two solutions ... sometimes it won't see below and there is one solution We looked at this triangle before. As you can see, you can try swinging the " line around, but no other solution makes sense. So this has only one solution. TrigonometriSinus, Cosinus, Tangen, Secan, Cosecan, Cotangen Berikut adalah rumus-rumus: Sinus, Cosinus, Tangen, Secan, Cosecan, Cotangen. Sinus Dalam trigonometri, hukum sinus ialah sebuah persamaan yang berhubungan dengan panjang sisi-sisi sebuah segitiga yang berubah-ubah terhadap sinus sudutnya. Jika sisi segitiga ialah (kasus sederhana) a, b dan c dan sudut yang berhadapan bersisi (huruf Rumus trigonometri dua sudut - sin a+b = sin a cos b + cos a sin b sin a-b = sin a cos b - cos a sin b cos a+b = cos a cos b - sin a sin b cos a-b = cos a cos b + sin a sin b sina+b= sin a cos b + cos a sin b cosa+b= cos a cos b - sin a sin b sina-b= sin a cos b - cos a sin b cosa-b= cos a cos b + sin a sin b - + - + sina+b + sina-b= 2 sin a cos b cosa+b + cosa-b= 2 cos a cos b sin a + sin b= 2 sin 1/2a+b cos 1/2a-b cos a + cos b= 2 cos 1/2a+b cos 1/2a-b sina+b= sin a cos b + cos a sin b cosa+b= cos a cos b - sin a sin b sina-b= sin a cos b - cos a sin b cosa-b= cos a cos b + sin a sin b - _ - _ sin a+b - sin a-b= 2 cos a sin b cosa+b - cos a-b= -2 sin a sin b sin a - sin b= 2 cos 1/2a+b sin 1/2a-b cosa-b - cos a+b= 2 sin a sin b cos a - cos b= -2 sin 1/2a+b sin 1/2a-b cos b - cos a= 2 sin 1/2a+b sin 1/2a-b Identitas Trigonometri - sin^2 x + cos^2 x = 1 ====>> r cos a^2 + r sin a^2= r^2 berdasarkan rumus pers O -> a^2 + b^2 = c^2 r^2 cos^2 a + r^2 sin^2 a= r^2 selain itu 2a=a+a r^2 cos^2 a + sin^2 a=r^2 cos^2 a + sin^2 a=1 sin 2x= 2 sin x cos x ====>> sina+a= sin a cos a + cos a sin a sin x= 2 sin 1/2x cos 1/2x = 2 sin a cos a cos 2x= cos^2 x - sin^2 x cos x= cos^2 1/2x - sin^2 1/2x = cos^2 x -1- cos^2 X dst''' = 2 cos^2 x - 1 =1- sin^2 x - sin^2 x = 1- 2 sin^2 x ====>>cos a+a= cos a cos a - sin a sin a =cos^2 a - sin^2 a tan 2x= sin 2x - cos 2x = 2 sin x cos x - cos^2 x - sin^2 x = 2 sin x cos x 1 - X - cos^2 x - sin^2 x cos^2 x = 2 tan x - 1- tan^2 x Aturan sinus dan cosinus - a b c a^2= b^ - 2bc cos A -=-=- b^2= a^ - 2ac cos B sin a sin b sin c c^2= a^ - 2ab cos C Bagaimana bisa menemukan rumus itu? Asumsi awal; berasal dari segitigalihat buku latihan Luas segitiga menggunakan aturan trigonometry - L= 1/2ab sin C L= 1/2ac sin B L= 1/2bc sin A RumusJumlah dan Selisih Sudut Cosinus. Rumus Jumlah Sudut Cosinus. Bukti: Perhatikan gambar berikut! Titik koordinat A dan B di atas diperoleh berdasarkan fungsi sinus dan cosinus. Selanjutnya perhatikan titik M yang ditransformasi dengan besar sudut putar dan sudut pusat O dari titik A. Dan perhatikan titik N yang ditransformasi dengan besar sin(a + b) = sin a . cos b + cos a . sin b. sin (a - b) = sin a . cos b - cos a . sin b. cos (a + b) = cos a . cos b - sin a . sin b. cos (a - b) = cos a . cos b + sin a . sin b. Bagian 1. Perkalian Sinus dan Sinus. Rumus perkalian sinus dan sinus diperoleh dari kedua rumus berikut: Bagian 2.Padagambar di atas, komponen vektor B yang tegak lurus vektor A adalah B sin Dengan menggunakan metode ini, kalian tidak perlu repot-repot menghafal rumus di atas. Perhatikan bagan berikut ini. Dengan menggunakan metode determinan tersebut, maka hasil perkalian silang antara vektor A dan vektor B di atas adalah sebagai berikut.
Darirumus jumlah dan selisih dua sudut, dapat diperoleh rumus sebagai berikut. sin (A + B) = sin A cos B + cos A sin B .. (1) sin (A - B) = sin A cos B - cos A sin B .. (2) dari persamaan (1) dan (2) dijumlahkan akan didapat : sin (A + B) + sin (A - B) = 2 sin A cos B atau 2 sin A cos B = sin (A + B) + sin (A - B) Rumus:2 Contoh Soal dan pembahasan jumlah dan selisih sinus. Diketahui sin α = 5/13 , sin β= 7/25, dan dan merupakan sudut tumpul. a. Tentukan sin (α + β) b. Tentukan sin (α - β) Pembahasan: Kita gunakan rumus sinus. Rumus sinus jumlah dua sudut : sin (α + β) = sin α cos β + cos α sin β. Rumus sinus selisih dua sudut :