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Solving Trig Equations

Ways to solve:

1. Isolate trig expression
2. Square root both sides
3. Factor
4. Square both sides
5. Rewrite using a single trig function

Example:

$cos(x)sin(x)=3cos(x),\ [0,\ 2\pi)$

$cos(x)sin(x)-3cos(x)=3cos(x)-3cos(x)$

$cos(x)sin(x)-3cos(x)=0$

$cos(x)(sin(x)-3)=0$

$sin(x)-3=0\rightarrow sin(x)-3+3=0+3\rightarrow sin(x)=3\rightarrow no\ solution$

$cos(x)=0\rightarrow x=\frac{\pi}{2}\ or\ \frac{3\pi}{2}$