2cos^2(3pi/2-x)= - sinx

Question

2cos^2(3pi/2-x)= - sinx

Answer 1

-2sin^2x=-sinx
-4cosxsinx=-sinx
-4cosxsinx+sinx=0 |:cosx
-4 tgx+tgx=o
-3tgx=0
tgx=0
x=Пn+nEZ