If tan ? = -2 and sin ? < 0, find sec ?.

Question

Choices are ;

 

- sqrt 5/2


sqrt 5


sqrt 5/2


- sqrt 5

Answer 1

All the trigonometric identities are true but there is not answer because it will be as of now = 1/cos = which is positive = 2/sin. being the two negative, so there is something missing to solve the problem. the angle is in the fourth quadrant.

Answer 2

Note that among the trig functions sin, cos, and tan, these are positive in the 4 quadrants: I: ALL, II: SIN, III: TAN, IV: COS

 

So if tan and sin are both negative, what quadrant must the angle (?) be in, and given secx=1/cosx, what sign must sec(?) be?

 

Also, given tanx=sinx/cosx, and given secx=1/cosx, how can you find the actual value of sec(?) ?