How do you solve $sin^2 x + 2 sin x cos x = 0$ ?

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Answer 1 · 2016-04-13T12:44:14

Hence solution is $x=npi$ or $x=npi+arctan(-2)$

As $sin^2x+2sinxcosx=0$

$sinx(sinx+2cosx)=0$

i.e. either $sinx=0$ i.e. $x=npi$

or $sinx+2cosx=0$ i.e. $sinx=-2cosx$ or $tanx=-2$

Hence $x=arctan(-2)$ or $x=npi+arctan(-2)$

Hence, $x=npi$ or $x=npi+arctan(-2)$

How do you solve sin^2 x + 2 sin x cos x = 0sin^2 x + 2 sin x cos x = 0?