Solve `sec theta-1=(sqrt(2)-1) tan theta`.

Answer

`theta=2npi or theta=2n pi +pi/4, n in Z`

Explanation

`sec theta-1=(sqrt(2)-1) tan theta`
`rArr ((1-cos theta)/(cos theta))=((sqrt(2)-1) sin theta)/(cos theta)`
or `2 sin^(2) (theta//2)=(sqrt(2)-1)2 sin (theta//2) cos (theta//2)`
or `sin (theta//2)=0, tan (theta//2)=(sqrt(2)-1)=tan (pi//8)`
`rArr theta//2=n pi or theta/2=npi +pi/8, n in Z`
`rArr theta=2n pi or theta=2 n pi +pi/4`