Question

Question #a44d8

Answer 1

Refer to the Explanation below.

Explanation:

The Derivative is OK.

As regards, `csctheta` can never be `0` for some `theta in RR`, because,

`csctheta=0 rArr 1/sintheta=0 rArr 1=0`, an impossible result.

In fact, `AA theta in RR-{kpi : k in ZZ}, |csctheta|>=1`.