Posted by meme on Sunday, February 19, 2012 at 12:16pm.
knowledge : point (3,4)is on the terminal arm of an angel (alpha) in stander position.verify that (sin alpha)2 + (cos alpha )2 =1

MATH  Steve, Sunday, February 19, 2012 at 12:41pm
FYI: angle, standard
hypotenuse h = √(3^2+4^2) = √25 = 5
sinθ = y/h = 4/5
cosθ = x/h = 3/5
sin^2θ + cos^2θ = (3/5)^2 + (4/5)^2 = 9/25 + 16/25 = 25/25 = 1