Question

5sin^2x-7sinxcosx+16cis^2x=4​

Answer 1

$\huge\boxed{\fcolorbox{black}{red}{answer}}$

5sin2x–7sinxcosx+16cos2x−4=0

Divide by cos2x

5tan2x−7tanx+16–4(1+tan2x)=0

tan2x−7tanx+12=0

(tanx−4)(tanx−3)=0

tanx=3or4⟹

$\boxed{\fcolorbox{green}{beige}{=tan−14 or tan−13}}$