Question

If sin A = 2/3
where 0° < A < 90°, what is the value of sin 2A

Answer 1

Looking at this question makes my brain hurt :(

Answer 2

if sin 2A = 2 * sin a * cos a
so find cos with cos(square) + sin(square) = 1

Answer 3

that would be x(square) + (2/3)(square) = 1

Answer 4

that gives us
cos a = squareroot(5)/3

Answer 5

now plug it in.
sin 2A = 2 * (2/3) * (squareroot(5)/3)
sin 2A = approx. 0.994

Answer 6

:P just took this a while ago. hope it's right. good luck