Question 879919
solve -3sin^2(theta)+3cos^2(theta)=0
 {{{-3sin^2(x)+3cos^2(x)=0}}}
 {{{-3(sin^2(x)-cos^2(x))=0}}}
(sin^2(x)-cos^2(x)=0
sin^2(x)-1+sin^2(x)=0
2sin^(x)=1
sin^2(x)=1/2
sin(x)=±√(1/2)=±√2/2
x=π/4, 3π/4, 5π/4, 7π/4