Question

f(x)=-根号3 sinx^2+sinxcosx.f(a/2)=1/4-根号3/2.则sina=

Answer 1

-根号3sinx^2+sinxcosx=-根号3*(1-cos2x/2)+1/2sin2x=根号3/2cos2x-根号3+1/2sin2x=sin(2x+60)-根号3/2 f(a/2)=sin(a+60)-3根号/2再有公式就可算出