Question

cos theta +cos pi=?
​

Answer 1

Answer:

cos(π + θ) = -cosθ,

tan(π + θ) = +tanθ,

cot(π + θ) = +cotθ.

Connecting the M that is in the 3rd Quadrant to O and extending it to cross the tangent and cotangent axes, it crosses them in their positive region, and hence, both are positive for angle π + θ.

Answer 2

Answer:

cos(π + θ) = -cosθ, tan(π + θ) = +tanθ, cot(π + θ) = +cotθ. Connecting the M that is in the 3rd Quadrant to O and extending it to cross the tangent and cotangent axes, it crosses them in their positive region, and hence, both are positive for angle π + θ.

l hope it helps you