How do I solve the Sin 3x equation?

Thread starter thenewbosco
Start date Sep 16, 2005
Tags

Sin

AI Thread Summary

To solve the equation sin 3x = 3 sin x - 4 sin^3 x, it is helpful to start by using the angle addition formula for sine, sin(3x) = sin(2x + x). This leads to the expression sin(3x) = sin(2x)cos(x) + cos(2x)sin(x). The next steps involve determining sin(2x) and cos(2x) using their respective double angle formulas. The discussion highlights the need for clarity on these formulas to proceed with the solution. Understanding these trigonometric identities is crucial for solving the equation effectively.

Sep 16, 2005

thenewbosco

no clue how to start this:

show

sin 3x = 3 sin x - 4 sin^3 x

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Sep 16, 2005

Dr Avalanchez

How to start this: sin(3x) = sin(2x+x)

Sep 16, 2005

thenewbosco

right so after doing this i get

sin 3x = sin2x(cos x) + (cos2x)(sin x)

whats next

Sep 16, 2005

Dr Avalanchez

sin(2x)=...?
cos(2x)=...?

Sep 16, 2005

thenewbosco

thanks for the help i got this and the others

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