Question

What is `7sectheta-4cos^2theta -costheta` in terms of `sintheta`?

Answer 1

`7sectheta-4cos^2theta-costheta`

`=>7/costheta-4cos^2theta-costheta`

`=>7/costheta-costheta-4cos^2theta`

`=>(7-cos^2theta)/costheta-4+4sin^2theta`

`=>(7-1+sin^2theta)/costheta+4sin^2theta-4`

`=>(6+sin^2theta)/sqrt(1-sin^2theta)+4sin^2theta-4`