Question

Question #97ded

Answer 1

-4/5.

Explanation:

Let `a=tan^(-1)(-4/3) in Q_4`, for principal value, and `Q_` and Q_4,

for the general value..

Then, `tan a = -4/3`, and the given expression

`sin a= -4/5`, for a in #Q_3 or Q_4. .