In which one of the following subsets , cos2A + sin2A = 1 is valid
0 A 90
sinA and cosA exists for A = 0∘ as sin0 = 0 and cos0 = 1
sinA and cosA exists for A = 90∘ as sin90 = 0 and cos90 = 0
We know sinA and cosA exists for any angle between 0 an 90.
Therefore the most appropriate subset would be option (d)