Question

If cos Θ = -2/5 and tan Θ > 0, what is the value of sin Θ? @Hero

Answer 1

\(\Large\rm \cos\theta\) is negative.
\(\Large\rm \tan\theta\) is positive.

So what quadrant does that put our angle \(\Large\rm\theta\) in?

Answer 2

Quadrant II?

Answer 3

my bad, quadrant IV

Answer 4

There's a uhhh weird acronym to help remember..
Lemme see if I can recall..

It's like.. "All Students Take Calculus" or maybe you've learned something similar :P I dunno.

ASTC,
All are positive in Q1,
Sine positive in Q2,
Tangent positive in Q3,
Cosine positive in Q4.

So if have tangent positive,
but not cosine,
we must be in Q3

Answer 5

So draw a triangle in Q3,