Question

How do you use the fundamental identities to simplify `cosusinu+tanucosu`?

Answer 1

`cosusinu+tanucosu=sinu(1+cosu)`

Explanation:

`cosusinu+tanucosu`

and as `tanu=sinu/cosu`

`cosusinu+tanucosu`

= `cosusinu+sinu/cosuxxcosu`

= `cosusinu+sinu`

= `sinu(1+cosu)`