- #1

- 78

- 0

I've been working on it for thirty minutes

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- Thread starter fiziksfun
- Start date

- #1

- 78

- 0

I've been working on it for thirty minutes

- #2

- 311

- 1

can u expand sin(3x) ?? and cos(2x)

just simplify both sides..and u'll get it..

- #3

- 290

- 2

You should use the identities

[tex]\cos{2\theta} = 1-2\sin^2{\theta}[/tex]

[tex]\sin{3\theta} = 3\sin{\theta} - 4\sin^3{\theta}[/tex]

Perhaps you were putting these identities in terms of cosines. When possible, stick with as few trig functions as possible and replace the [tex]\cos^2{\theta}[/tex] with [tex]1-\sin^2{\theta}[/tex] or vice versa.

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