(COSA) 2 / (SINB) 2 + (Sina) 2 / (Cos2) = 1 It's not (Cos2), it's (CoSb) &; It's not a + B = 45 degrees, it's a + B = 90 degrees a,b∈(0,90°)

(COSA) 2 / (SINB) 2 + (Sina) 2 / (Cos2) = 1 It's not (Cos2), it's (CoSb) &; It's not a + B = 45 degrees, it's a + B = 90 degrees a,b∈(0,90°)

If a + B = 45 degrees, a = 0, B = 45 degrees are not equal
What's more, if a + B = 90 ° then Sina = CoSb cosa = SINB, then the original formula is equal to 2