How do you prove $(2tanx)/ (1+tan^2 x) = sin 2x$ ?

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Answer 1 · 2016-09-18T07:50:14

Please see below.

$(2tanx)/(1+tan^2x)$

= $(2sinx/cosx)/sec^2x$

= $(2sinx/cosx)/(1/cos^2x)$

= $(2sinx)/cosx xx cos^2x/1$

= $2sinxcosx$

= $sin2x$

How do you prove (2tanx)/ (1+tan^2 x) = sin 2x(2tanx)/ (1+tan^2 x) = sin 2x?