Find the general solutions of the following equation: `sin 2theta+costheta=0`

Explanation

We have `sin2theta+costheta=0`

or `costheta=−sin2theta=cos(π/2+2theta)`

`⇒theta=2nπ±(π/2+2theta)`

Taking positive sign, we have

`theta=2nπ+π/2+2theta`

`theta=2nπ−π/2`

Taking negative sign, we have

`theta=2nπ−(π/2+2theta)`
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