In ` A B C ,` prove that `cos e c A/2+cos e c B/2+cos e c C/2geq6.`

If I is the incenter of a triangle ABC, then the ratio I A : I B : I C is equal to a) cos e c A/2: cos e c B/2: cos e c C/2 b) sinA/2:sinB/2:sinC/2 c) secA/2:secB/2:secC/2 d) none of these

If A+B+C=180^0 , prove that : cos^2, A/2 + cos^2, B/2 - cos^2, C/2 = 2cos, A/2 cos, B/2 sin, C/2

In a triangleABC, prove that a cos A+b cos B+c cos C=2a sin B sin C

If A+B+C=pi , prove that cotA+cotB+cotC-cos e cAdotcos e cBdotcos e cC=cotAdotcotBdotcotCdot

In any triangle ABC, prove that a cos A+b cos B +c cos C =(8 triangle^(2))/(abc) .

Expand cos ( A + B + C). Hence prove that cos A cos B cos C = sin A sin B cos C + sin B sin C cos A + sin C sin A cos B, if A + B + C = (pi)/(2) .

In A B C Prove that cos^2A/2+cos^2B/2+cos^2C/2lt=9/4dot In cos^2A/2+cos^2B/2+cos^2C/2=y(x^2+1/(x^2)) then find the maximum value of ydot

If A + B + C = 180^(@) , prove that cos A + cos B - cos C = -1 + 4 cos (A)/(2) cos"" (B)/(2) sin"" (C )/(2)

If A + B + C = (pi)/(2) , prove that cos 2A + cos 2B + cos 2C = 1 + 4 sin A sin B cos C