In `DeltaABC, a=4, b=6, c=8`, then find the value of `8 cos A + 16 cos B + 4 cos C`.

In DeltaABC , a=7, b=5 and c=8, then find the value of cos2B.

In DeltaABC, a = 3, b = 5, c = 6 , find the value of : cos (A/2)

Find the value of cos^4 (pi / 8)

In a Delta A B C , If a=18 ,\ b=24 ,\ c=30 , find the value of cos A ,\ cos B\ a n d\ cos Cdot

Let A,B,C be the three angles such that A+B+C=pi , tan A.tan B=2 , then find the value of (cos A cos B)/(cos C)

If a=16, b=24 and c=20, then the value of cos(B/2) is

If a = 4, b = -5, c = -8, find the value of (a+b) times c .

In DeltaABC , if a=6, b=8, c=10, evaluate cos2A.

If DeltaABC is right angled at C , then the value of cos(A+B) is

If sin A + sin^2 A + sin^3 A = 1 , then find the value of cos^6 A-4 cos^4 A + 8 cos^2 A .