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Tan2 theta - sin2 theta= sin2 theta × tan2 theta


1 Answer

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Hi there!

We can begin by solving the left side:

tan²Θ - sin²Θ =

Rewrite tan:


(sin^2\theta)/(cos^2\theta) - sin^2\theta =

Multiply sin²Θ by cos²Θ to get a common denominator:


(sin^2\theta)/(cos^2\theta) - (sin^2\theta * cos^2\theta)/(cos^2\theta)=

Subtract:


(sin^2\theta- sin^2\theta * cos^2\theta)/(cos^2\theta) =

Factor out sin²Ф from the numerator:


(sin^2\theta(1 - cos^2\theta))/(cos^2\theta) =

Rewrite 1 - cos²Ф as sin²Ф (Pythagorean identity)


(sin^2\theta(sin^2\theta))/(cos^2\theta) =

Simplify:


(sin^4\theta)/(cos^2\theta) =

Split into sin and tan:


sin^2\theta * (sin^2\theta)/(cos^2\theta) =

Rewrite:


sin^2\theta * tan^2\theta

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