Question

Question #25950

Answer 1

`2sin^2x-6cos2x=0`

`=>1-cos2x-6cos2x=0`

`=>cos2x=1/7=cos(81.78^@)`
And
`cos2x=cos(360-81.78)^@=278.22^@`

So `x=81.78/2=40.89^@`

and `x=278.22/2=139.11^@`

Again

`cos2x=cos(360+81.78)^@=441.78^@`
`=>x=441.78/2=220.89^@`

`cos2x=cos(720-81.78)^@=638.22^@`
`=>x=638.22/2=319.11^@`