In A B C ( a − b ) 2 cos 2 C 2 + ( a + b ) 2 sin 2 C 2 =

Question

In A B C ( a − b ) 2 cos 2 C 2 + ( a + b ) 2 sin 2 C 2 =, b 2, c 2, a 2, a 2 + b 2 + c 2

MARKS App · Accepted Answer

Let X = a - b 2 cos 2 ⁡ C 2 + a + b 2 sin 2 ⁡ C 2 = ( a 2 + b 2 ) ( cos 2 ⁡ C 2 + sin 2 ⁡ C 2 ) - 2 a b ( cos 2 ⁡ C 2 - sin 2 ⁡ C 2 ) = a 2 + b 2 - 2 a b cos ⁡ C = c 2 ∵ ( c o s i n e rule )

Search any question & find its solution

Looking for more such questions to practice?