Given tan theta=-8/5 and sin theta < 0, find cos theta.

Answer 1

Tan theta = -(8/5). = Y/X.

Tan theta < 0, and Sin theta < 0: Q4.

r^2 = 5^2 + 8^2 = 89,
r = 9.43398.

Cos theta = X/r = 5/9.43398=0.52999894,