Prove that in triangle `A B C ,cos^2A+cos^2B-cos^2C=1-2sinAsinBcosCdot`

In a triangle ABC,cos^(2)A+cos^(2)B+cos^(2)C=

Prove that in triangle ABC , cos^(2)A + cos^(2)B + cos^(2)C lt 3/4 .

In triangle ABC,cos A+2cos B+cos C=2, then-

Prove that, in a triangle ABC, b(a cos C - c cos A) = a^2 - c^2

Statement-1: In a triangle ABC, if sin^(2)A + sin^(2)B + sin^(2)C = 2 , then one of the angles must be 90 °. Statement-2: In any triangle ABC cos 2A + cos 2B + cos 2C = -1 - 4 cos A cos B cos C

In triangle ABC, cos^2A + cos^2B - cos^2C = 1, then the triangle is necessarily

For any triangle ABC,prove that a cos A+b cos B+c cos C=2a sin B sin C

In any triangle ABC, prove that: a cos A+b cos B+c cos C=2a sin B sin C

If A+B+C=180, prove that cos^(2)A+cos^(2)B+cos^(2)C=1-2cos A cos B cos C

In any triangle ABC, prove that following: quad a cos A=b cos B=c cos C=2b sin A sin C=2c sin A sin B