By considering the real and imaginary parts of the product eiθ eiφ prove the standard formulae for cos(θ +φ) and sin(θ +φ) .

Q: Find sin π/4, cos π/4, and tan π/4.

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Q: From the formula of sin (A + B), deduce the formulae of cos(A+ B) and cos (A- B).

A: To derive formula cos(A+B) & cos(A-B) using formula of sin(A+B)

Q: Derive the cosine formula a2 = b2 + c2 – 2bc cos A and the sine formula sin A sin B sin C а b C…

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Q: tanla= 2 with 3T LaL2p 3 2 and Sin lb) = 3 with IT L6LT 2. %3D

A: Solution:-  tana=-23   with 3π2<a<2π (fourth quadrant) sinb=34 with    π2<b<π   (second…

Q: Convert r=1/1+sinθ to Cartisian

A: I am going to solve the given problem by using some simple algebra to get the required result.

Q: Use the cosine of a sum and cosine of a difference identities to find cos (s + t) and cos (s- t). 4…

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Q: Write the formulas for cos(A - B) and sin (A - B)?

A: We have to write the formulas for cosA-B and sinA-B. We know the formula for cosine difference angle…

Q: Find cos(A - B). cos A = V10 and sin B = ,where 0° <A<90° and 270° <B< 360°. 10 O V10-3 30 20 O…

A: Given query is to find cos (A-B).

Q: Find cos A

A: Explanation of the solution is given below...

Q: Find cos ⁡(2θ) if sin (θ) = 2/13.

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Q: Evaluate 1- Sin L Cos L do 2- ( sing ecasy Sdt J-t44t-3 3-

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Q: Evaluate cos 1 (2+3i).

A: Given :    cos-12+3i

Q: Find sin(2θ), if cosθ=24/25 and θ lies inquadrant IV.

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Q: Derive the 3rd formula for cos(2A) Hint: Use the 1st Formula for cos(2A) and use the Pythagorean…

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Q: Find cos C if a = 8, b = 7, and c = 15.

A: If the sum of squares of two sides is equal to the square of the third side, then these types of…