ત્રિકોણ ABC માં , {sin ^2}frac{A}{2} + {sin ^2}frac{B}{2} + {sin ^2}frac{C}{2} =

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3.Trigonometrical Ratios, Functions and Identities

easy

ત્રિકોણ $ABC$ માં , ${\sin ^2}\frac{A}{2} + {\sin ^2}\frac{B}{2} + {\sin ^2}\frac{C}{2} = . . . .$

A

$1 - 2\,\cos \frac{A}{2}\cos \frac{B}{2}\cos \frac{C}{2}$

B

$1 - 2\,\sin \frac{A}{2}\cos \frac{B}{2}\cos \frac{C}{2}$

C

$1 - 2\,\sin \frac{A}{2}\sin \frac{B}{2}\sin \frac{C}{2}$

D

$1 - 2\,\cos \frac{A}{2}\cos \frac{B}{2}\sin \frac{C}{2}$

Solution

(c) Trick: For $A = B = C = {60^o}$ only option $(c)$ satisfies the condition.

Standard 11

Mathematics

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