Solve `4costheta-3sectheta=tantheta`

Explanation

`4costheta - 3sec theta - tan theta = 0`

`4costheta - 3/costheta - sintheta/costheta = 0`

`=>4cos^2 theta - sin theta - 3 = 0`

`=>4(1-sin^2theta) - sin theta - 3 = 0`

`=>4sin^2theta +sin theta - 1 = 0`

`=>sintheta = (-1+-sqrt(1-4(4)(-1)))/(8)`,

`=>sin theta = (-1+sqrt17)/8 and sin theta = (-1-sqrt17)/8`

`=>theta = npi+(-1)^nsin^-1( (-1+sqrt17)/8) and theta = npi+(-1)^nsin^-1( (-1-sqrt17)/8)`