If 2 = t,then 1 - t^2 1 + t^2 is equal to - Vidyadip

MCQ

If $\tan \frac{\theta }{2} = t,$then $\frac{{1 - {t^2}}}{{1 + {t^2}}}$is equal to

✓
$\cos \theta $
B
$\sin \theta$
C
$\sec \theta $
D
$\cos 2\theta $

✓

Answer

Correct option: A.

$\cos \theta $

a
(a) $\tan \frac{\theta }{2} = t$

$ \Rightarrow \frac{{1 - {{\tan }^2}\frac{\theta }{2}}}{{1 + {{\tan }^2}\frac{\theta }{2}}} = \cos \theta $.

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