Question

if sin x > 0 and cos x = -4/5, then tan x =
(a) 3/5
(b) -3/5
(c) 4/3
(d) -3/4
(e) -4/3

Answer 1

Hint it must be negative :P
because it is in second Quadrant.

Answer 2

how do you know it's in the 2nd quadrant?

Answer 3

Because sin is positiv in second Quadrant and cos is negative.

Answer 4

so then calculating the rest the answer comes:
\[\huge (d) \ -3/4\]