60. If sin2e + sin2th = and. cos20 + cos2kp = 3, so the value of cos2 (6 -) is (B)% ___ (C) (D) 5

cos2B + cos2A-cos2C = 1-4sin A sin B cos C

cos2a-cos2b + cos2c = 1-4sin a cos b sin c

If sin2 theta+sin2 phi=(1)/(2) and cos2 theta+cos2 phi=(3)/(2), then cos^(2)(theta-phi)=(A)(3)/(8)(B)(5)/(8)(C)(3)/(4)(D)(5)/(4)

If A+C=2b, then the value of (cos C - cos A)/(sin A-sin C) is-

if sin A-sin B=c and cos A-cos B=d then cos ec^(2)((A+B)/(2))

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 .

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

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 .

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 .