Question

How do you evaluate the expression `csc(-60)`?

Answer 1

`color(brown)(csc (-60) = - 1/ sin 60 = - 2/ sqrt3`

Explanation:

`csc (-60) = csc (-(pi/3)) = csc (2pi - (pi/3)`

It falls in IV quadrant where in `cos , sec` alone are positive.

`:. color(indigo)(csc (-60) = - csc (60) = - 1 / sin 60 = -1 / (sqrt3/2) = - 2 / sqrt3`