Question #515ea

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Answer 1 · 2017-04-08T18:51:42

$theta = 90^@$ and $theta = 270^@$

Given: $sin^2(theta)cos(theta)=cos(theta)$

Subtract $cos(theta)$ from both sides:

$sin^2(theta)cos(theta)-cos(theta)=0$

Factor:

$(sin^2(theta)-1)cos(theta)=0$

$sin^2(theta)-1= 0 and cos(theta)=0$

$sin^2(theta)=1 and cos(theta)=0$

$sin(theta)=+-1 and cos(theta)=0$

$sin(theta) = 1$ at $90^@$

$sin(theta) = -1$ at $270^@$

The same angles solve the $cos(theta)=0$ equation