Question

if tan a = -5/12 and cos a> 0, find sin a

Answer 1

tan(a) = sin(a) / cos(a) = -5/12
Since cos(a) > 0, sin(a) must be < 0.

Answer 2

First find AC using Pythagoras Theorem.
sin(a) = BC / AC = 5/?
Put a negative sign in front of it to make sin(a) < 0.

Answer 3

How do I do that I don't know how

Answer 4

Pythagoras theorem: AC^2 = AB^2 + BC^2 = 12^2 + 5^2 = 144 + 25 = 169
AC = sqrt(169) = 13
|sin(a)| = BC/AC = 5/13
Put a negative sign to make sin(a) negative.
sin(a) = -5/13

Answer 5

Thanks

Answer 6

welcome.