Question

Which identity is used for \(\sin^3 x\)?

Options

• \(\sin 3x = 3\sin x - 4\sin^3 x\)

• \(\sin^3 x = 3\sin x - 4\sin 3x\)

• \(\sin 3x = 3\sin x + 4\sin^3 x\)

• \(\cos 3x = 3\cos x - 4\cos^3 x\)

Answer 1

The triple-angle identity \(\sin 3x = 3\sin x - 4\sin^3 x\) contains \(\sin^3 x\). It can be rearranged when integrating a cubic power of sine.