## Ask Singapore Homework?

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We use a series of double-angle formulae to do this question. Note that the angle pair does not have to be specifically 2x and x; as long as one angle is twice of another, the formula remains valid.

In other words,

sin 2x = 2 sin x cos x

sin 4x = 2 sin 2x cos x

(because 2x is twice of x while 4x is twice of 2x)

In other words,

sin 2x = 2 sin x cos x

sin 4x = 2 sin 2x cos x

(because 2x is twice of x while 4x is twice of 2x)

Date Posted:
9 months ago