SOLUTION: Prove that sin^2 x + cos^2 x=1

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Question 1027996: Prove that sin^2 x + cos^2 x=1
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
For any angle x of a right triangle, let a be the adjacent side of the angle and b be the opposite side of the angle and c be the hypotenuse of the triangle.
From the Pythagorean theorem,
a%5E2%2Bb%5E2=c%5E2
But you also know from trigonometry,
cos%28x%29=a%2Fc
sin%28x%29=b%2Fc
So then continuing from the equation above,
a%5E2%2Fc%5E2%2Bb%5E2%2Fc%5E2=1
cos%5E2%28x%29%2Bsin%5E2%28x%29=1