(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Use double-angle and addition formulæ and other relations for trigonometrical functions to find an expression for sin(3x) in terms of sin x alone.

My problem is I don't know what is meant by "find an expression for sin(3x) in terms of sin x alone.". I know the relevant formulae but do not know what is actually wanted of the question. I know I can 'split' it by going sin(2x + x) then using addition formulae... But I don't know why or what is expected as a final answer. An equation involving only sin and no cos?

2. Relevant equations

Trig identities, addition formulae

3. The attempt at a solution

No idea.

PS. I found the answer online but had no idea why that's the answer - please don't just give me the answer :).

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# Homework Help: Finding an expression for (e.g. sin (3x)) in terms of (e.g. sin x) alone?

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