Which of the following is the coefficient of x3 in the Maclaurin series for f(x) = sin(2x)?

Question

Which of the following is the coefficient of x³ in the Maclaurin series for f(x) = sin(2x)?

Answer 1

sinx = x - x³ / 3! + x⁵ / 5! - x⁷ / 7! + ...

So, sin(2x) = 2x - (2x)³ / 3! + (2x)⁵ / 5! - ...

Coefficient of x³ is -(2)³ / 3! = -8/6 = -4/3

Answer 2