If SinA equals minusxdividedy then cosA equals?

Answer 1

sin A = -x/y

Since the sine is the ratio of the opposite leg to the hypotenuse, let's assume the opposite leg's length is -x and the hypotenuse's length is y. Let's call the adjacent leg's length z. So:

(-x)2+z2=y2

z2=y2-(-x)2

z2=y2-x2

z=√(y2-x2)

cos A = z/y = √(y2-x2)/y