2tan²xsinx - tan²x = 0
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Transpose tan²x to the right side of the equation
2tan²xsinx = tan²x
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Divide the whole equation with tan²x
tan²x will be cancelled out
tan²x ÷ tan²x = 1
2sinx = 1
sinx = 1/2
x = arcsin(1/2)
x = 30degrees or π/6