MHB Proving Trig Identity: (Sin2x-tanx)/cos2x=tanx

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The discussion focuses on proving the trigonometric identity (Sin2x - tanx) / cos2x = tanx. Participants suggest using the identities sin 2x = 2 sin x cos x and tan x = sin x / cos x to simplify the right-hand side. The next step involves combining the terms in the numerator into a single fraction with a common denominator. Factorization of the resulting expression is recommended to facilitate further simplification. The goal is to demonstrate the equality through these algebraic manipulations.
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May someone kindly assist me to prove this trig identity

(Sin2x-tanx) / cos2x = tanx

Thank you for your assistance
 
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paix1988 said:
May someone kindly assist me to prove this trig identity

(Sin2x-tanx) / cos2x = tanx

Thank you for your assistance

Making use of the identities $\sin 2x = 2 \sin x \cos x$ and $\tan x = \sin x / \cos x$ we can write the RHS as:
$$\frac{2 \sin x \cos x -\frac{\sin x}{\cos x}}{\cos 2x}.$$
To proceed, write the numerator as one fraction (thus with denominator $\cos x$) and factorize!
 
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