Question

How do you solve (2senx+1)(2cosx+3)=0 ?

Answer 1

Please see below.

Explanation:

.

`(2sinx+1)(2cosx+3)=0`

`2sinx+1=0, :. sinx=-1/2, x=+-2kpi+(7pi)/6, +-2kpi+(11pi)/6`

`2cosx+3=0, :. cosx=-3/2`, this is not valid because `cosx` values are between `+1` and `-1`.