Question

Sin x cos x = -cos x
Find all angles that satisfy the equation below

Answer 1

`x=90^\circ,270^\circ`

Explanation:

`sinxcosx=-cosx`

`sinxcosx+cosx=0`

`cosx(sinx+1)=0`

`cosx=0`

`x=90,270`

`sinx+1=0`

`sinx=-1`

`x=270`

Therefore, the angles that satisfy the equation are
`x=90^\circ,270^\circ`