" 15] In "Delta ABC" prove that "a^(2)=b^(2)+c^(2)-2bc cos A

In Delta ABC prove that a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

In Delta ABC, prove that a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

In any Delta ABC, prove that :a^(2)+b^(2)+c^(2)=2(bc cos A+ca cos B+ab cos C)

In Delta ABC, prove that cos A=(b^(2)+c^(2)-a^(2))/(2bc) by vector method.

In any Delta ABC, prove that b^(2)sin2C+c^(2)sin2B=2bc sin A=4Delta

In any Delta ABC, prove that :(b^(2)-c^(2))/(cos B+cos C)+(c^(2)-a^(2))/(cos C+cos A)+(a^(2)-b^(2))/(cos A+cos B)=0

In any Delta ABC, prove that cos C=(a^(2)+b^(2)-c^(2))/(2ab) with the help of vectors

In Delta ABC prove that 2(b cos^(2)((C)/(2))-c cos^(2)((B)/(2)))=a+b+c

In Delta ABC , prove that (b - c)^(2) cos^(2) ((A)/(2)) + (b + c)^(2) sin^(2) ((A)/(2)) = a^(2) .

In Delta ABC prove that a^2(cos^2B - cos^2C) + b^2(cos^2C - cos^2A) + c^2(cos^2A - cos^2B) = 0