Question
[
1 e+x=cos theta
]
( frac{1}{sqrt{2}} quad underline{c} cos theta leq 1 )
[
begin{aligned} cos left(frac{pi}{4}right) & leq cos theta leq cos (0) frac{pi}{4} / 2 &left(0 leq 0 leq frac{pi}{4}right)=0 leq 20 leq pi end{aligned}
]
( sin left(2 cos theta sqrt{left.1-cos ^{2} thetaright)}=2 cos ^{-1}(cos theta)right. )
Sim ( (sin 2 theta)=2 cos ^{-1}(cos theta) )
Hence proved
as we are getting ( 2 theta=2 theta quad & quad ) condition 5 are satisfied

(ii) sin" (2xv1 – x2) = 2 cos x, TSx51
Solution
