If `Delta`ABC is right triangle and if `angleA = (pi)/(2)`, then prove that
`cos^(2)B + cos^(2)C = 1`

If Delta ABC is right triangle and if angleA = (pi)/(2) , then prove that sin^(2) B + sin^(2)C = 1

If Delta ABC is right triangle and if angleA = (pi)/(2) , then prove that cos B - cos C = -1 + 2 sqrt(2) cos"" (B)/(2) sin"" (C )/(2) .

If triangleABC is a right triangle and if angleA=pi/2 , then prove that (i) cos^(2) B+cos^(2)C=1 (ii) sin^(2) B+sin^(2) C=1 cos B-cos C=-1+2 sqrt2 cos""B/2sin ""C/2

ABC is a right angled triangle with angleA=90^(@) .Then the value of cos^(2)A+cos^(2)B+cos^(2)C is :

If ABC is a right angled triangle, then the value of (cos ^(2)A +cos ^(2) B+ cos ^(2)C) is -

If A, B, C are interior angles of triangle ABC, prove that :- cos^2(A/2)+cos^2((B+C)/2)=1 .

If in triangle ABC ,b^2=a(c+a) and c^2=(a+b)b then prove that cosAcos B cos C=(-1/8)

In a Delta ABC, angleA = 60^(@), prove that b + c = 2a cos ((B - C)/(2)) .

In triangle ABC,/_C=(2 pi)/(3) then the value of cos^(2)A+cos^(2)B-cos A*cos B is equal