Question

How do I find the value of csc-240?

Answer 1

Find csc(240).

Ans: - `(2sqrt3)/3`

Explanation:

`csc (240) = 1/(sin (240))`. Find sin (240)

Use the trig identity: sin (a + b) = sin a.cos b + sin b.cos a
sin (240) = sin (180 + 60) =
= sin 180.cos 60 + sin 60.cos 180 = 0 + ( -1)(sqrt3/2) = - `sqrt3/2`.

`csc (240) = 1/(sin) = - (2sqrt3)/3`