Question

sin theta +2 cos theta = 1 . prove that 2 sin theta - cos theta = 2
??

Answer 1

Let 2sin theta-cos theta=x..........(1)
given:sin theta+2cos they=1..........(2)
Now,add the squares of (1)&(2)
(2sin theta-cos there)^2+(sin theta +2 cos theta)^2=x^2+1
4sin^2 theta-4 sin theta×cos theta +cos^2 theta+sin^2 theta + 4 sin theta× cos theta+ 4cos^2 theta=x^+1
5sin^2 theta +5cos^2=x^2+1
5(sin^2theta+cos^2theta)=x^2+1
x^+1=5(since sin^2 theta +cos^2 theta=1)
x^2=4
x=+2 or -2

Answer 2

Answer:

Hope it helps you friend.