sin(2x) is a double-angle identity.
sin(2x) = 2sin(x)cos(x)
You can find cos(x) using the Pythagorean identity.
cos(x) = - √(1 - sin2(x))
sin(x) is already given to you. Just plug it in to find cos(x). Then multiply them together to get sin(2x).
sin(2x) = - 2sin(x)√(1 - sin2(x))