Question

tan theta = -4/7 theta and find cos theta?

Answer 1

theta=tan^-1(-4/7)

Answer 2

Hmm there's not enough information in this question.
Tangent is negative in quadrants 2 and 4.

If we draw a triangle in quadrant 2, our cosine is negative.
If we draw our triangle in quadrant 4, our cosine is positive.

We need more information :(

Answer 3

theta is in second quadrant, tan theta = -4/7 , find cos theta

Answer 4

Which side should we give the negative to?
The 4 or the 7?

Answer 5

..?