Question #47049

1 Answer
Nov 22, 2016

y = +-sqrt(1/2 - 1/2x)" "{x|-1 ≤ x ≤ 1}

Explanation:

y = sin(t) -> t = arcsiny

We know that cos(2alpha) = 1 - 2sin^2alpha:

x = 1 - 2sin^2(t)

x = 1 - 2sin^2(arcsiny)

x = 1 - 2y^2

Since it is often better regarded to have a function defined by y:

x - 1 = -2y^2

-1/2x + 1/2= y^2

y = +-sqrt(1/2 - 1/2x)

However, we must restrict the function.

The domain of y = arcsinx and y = arccosx is -1 ≤ x ≤ 1.

Hopefully this helps!