Question

Sin(180-x) X tan(360-x) X cos(180+x) - 1

Answer 1

Use the supplementary angle property

Sin(180-x)*tan(360-x)*cos(180+x) - 1
= sinx * (-tanx) * (-cosx) - 1
= sinx(-sinx/cos)(-cosx) - 1
= sin^2 x - 1
= -1(1 - sin^2 x)
= -cos^2 x