Question

cos(pi+x)/cos((3pi/2)-x)=cotx prove

Answer 1

[cos(pi)cosx - sin(pi)sinx]/[cos(3pi/2)cosx + sin(3pi/2)sinx]
=(-cosx)/(-sinx)
=cotx

Answer 2

\[\cos(x+\pi)=-cos x\]
\[\cos(3\pi/2-x)=-sin x\]
\[-\cos x/-\sin x=\cot x\]