# What is the right choice for question 40) ? http://postimg.org/image/e7075r4nt/

### 1 Answer | Add Yours

Usually cotangent can be written as;

`cotx = 1/tanx`

We know that `tanx = (sinx)/(cosx)`

Therefore;

`cotx = 1/((sinx)/(cosx)) = (cosx)/(sinx)`

`cotx = (cosx)/(sinx)`

We know that;

`secx = 1/cosx rarr cosx = 1/secx`

`csc = 1/sinx rarr sinx = 1/cscx`

`cotx = (cosx)/(sinx)`

`cotx = (1/secx)/(1/cscx)`

`cotx = (cscx)/(secx)`

*So the correct choice is d)*