Question

a.sin2x=1/2
b.cos(sx+pi/4)=1
c.sin4x=sin2x
d.cos3x+cos5x=0

Answer 1

[tex]sin2x= \frac{1}{2} \\ 2x=(-1)^karcsin\frac{1}{2}+k\pi\\ 2x=(-1)^k\cdot \frac{\pi}{6} +k\pi|:2\\ x=(-1)^k\cdot \frac{\pi}{12} +k\frac{\pi}{2},k \in Z[/tex]