Home
Class 11
MATHS
Prove that costhetacos""(theta)/(2)-cos3...

Prove that `costhetacos""(theta)/(2)-cos3 thetacos""(9theta)/(2)=sin7thetasin8theta`.

Text Solution

AI Generated Solution

To prove the identity \[ \cos \theta \cos \frac{\theta}{2} - \cos 3\theta \cos \frac{9\theta}{2} = \sin 7\theta \sin 8\theta, \] we will start with the left-hand side (LHS) and simplify it step by step. ...
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC FUNCTIONS

    NCERT EXEMPLAR|Exercise LONG ANSWER TYPE QUESTIONS|10 Videos

  • TRIGONOMETRIC FUNCTIONS

    NCERT EXEMPLAR|Exercise OBJECTIVE TYPE QUESTIONS|31 Videos

  • STRAIGHT LINES

    NCERT EXEMPLAR|Exercise MATCHING THE COLUMN|3 Videos

Similar Questions

Explore conceptually related problems

Prove that: cos theta(cos theta)/(2)-cos3 theta(cos(9 theta))/(2)=sin7 theta s in8 theta

Prove that: cos2theta.costheta/2-cos3theta.cos(9theta)/(2)=sin5theta.sin(5theta)/(2)

Prove that costhetacos((theta)/(2))-cos3thetacos((9theta)/(2))="sin"((7theta)/2)"sin"4theta

Prove that: cos 2theta"cos"(theta)/(2)-cos 3theta cos((9theta)/2)="sin" 5theta "sin"((5theta)/2) .

cos3thetacos5theta-cos7thetacos9theta=0

Prove that : (1+sin2 theta-cos 2theta)/(sin theta+cos theta)=2sin theta

Prove that (cos theta-sin theta)/(cos theta+sin theta)=sec2theta-tan2theta

Prove that cos^(3)thetasin3theta+sin^(3)theta cos 3theta=(3)/(4)sin 4 theta .

cos (2 theta) cos ((theta) / (2)) - cos (3 theta) cos ((9 theta) / (2)) = sin (5 theta) sin ((5 theta) / (2))

Prove that : (cos4 theta+cos3 theta+cos2 theta)/(sin4 theta+sin3 theta+sin2 theta)=cot3 theta