How to prove [2tan⁡(𝑥/2)]/{1+[tan(𝑥/2)]^2} = sin⁡𝑥?

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Trigonometric Identities Part 3. Start solving the fractional form left-hand side members of the given equation, [2tan(x/2)]/{1+[tan(x/2)]^2}, until the right-hand side member of the given equation, sinx, is obtained. As we replace tan(x/2) by [sin(x/2)]/[cos(x/2)], and {1+[tan(x/2)]^2} by [sec(x/2)]^2 we get {2[sin(x/2)]/[cos(x/2)]}/{[sec(x/2)]^2}. Now, as we replace [sec(x/2)]^2 by 1/{[cos(x/2)]^2}, we get {2[sin(x/2)]/[cos(x/2)]}/(1/{[cos(x/2)]^2}). Evaluate and simplify.

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