Question

Question #5b278

Answer 1

`tan^2x+4secx=4`

`=>sec^2x-1+4secx=4`

`=>sec^2x+4secx+2^2=4+4+1`

`=>(secx+2)^2=9`

`=>secx+2=pm3`

`secx=1`

`=>cosx=1`

`x=2npi" where "n in ZZ`

Again

`secx=-3-2=-5`

`=>cosx=-1/5=cos(2.09rad)`

`=>x=2npipm2.09" where " n in ZZ`