In a triangle `ABC`, `a^4+b^4+c^4=2c^2(a^2+b^2)` prove that `C=45^@` or `135^@`

In a triangle ABC if a^4+b^4+c^4=2c^2(a^2+b^2) , then angle C is equal to (A) 60^0 (B) 120^0 (C) 45^0 (D) 135^0

In a triangle ABC, if a=2,b=4,c=5 then cosB=

In a triangle ABC, if a=2,b=4,c=5 then cosA=

In any triangle ABC, prove that: Delta=(b^(2)+c^(2)-a^(2))/(4cot a)

If in a triangle ABC ,b +c=4a then cot(B/2)cot(C/2) is equal to

In a triangle ABC prove that a/(a+c)+b/(c+a)+c/(a+b)<2

In triangle ABC , prove that b^2sin2C+c^2sin2B=2bcsinA .

In triangle ABC , prove that a^2sin(B-C)=(b^2-c^2)sinA .

If, in Delta ABC, a^(4) + b^(4) + c^(4) = 2a^(2)(b^(2) + c^(2)) then : m/_A = ...