Question

How do you solve `cos x= -0.7` over the interval 0 to 2pi?

Answer 1

`cosx=-0.7=-cos45.57^@`

`=>cosx=cos(180-45.57)^@`
So `x=134.43^@`

Again
`=>cosx=cos(180+45.57)^@`

`=>x=225.57^@`