Question

solve this question​

Answer 1

Cos^-1(3/5cosx+4/5 sinx)=x

3/5 cosx +4/5 sin x =cos x

4/5 sin x = cos x-3/5 cosx

4/5 sin x=cosx(1-3/5)

4/5 sinx =2/5 cos x

sin x /cos x=1/2

Tan x=1/2

x=Tan^-1(1/2)=26.57 degree

Answer 2

above solution is correct from the trigonometry