ok ... found an identity at this link that may help.

List of trigonometric identities - Wikipedia, the free encyclopedia

where ...

and

if

if

I'd let and see where that goes.

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- September 6th 2010, 05:24 PM #1

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## Sin and Cos

How do I solve this? I have been working on this same problem for about an hour and can't come up with anything. I have to find the value of A, w, and b.

2sin(12x + 1) + 3sin(12x + 3) = A sin(wx + b)

Any help (with steps included) would be GREATLY appreciated! Thanks!

- September 6th 2010, 07:09 PM #2
ok ... found an identity at this link that may help.

List of trigonometric identities - Wikipedia, the free encyclopedia

where ...

and

if

if

I'd let and see where that goes.

- September 6th 2010, 07:43 PM #3

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Hello, aeagan2!

Wow . . . This took a lot of work!

I assume you know the Compound Angle Identities:

. .

. .

We have:

. .

. . . . . . . . . .

. .

. . . . . . . . . .

. .

. . . . . . . . . .

Equate "corresponding parts":

. .

Let: .

[2] and [1] becomes: .

Divide [3] by [4]: .

. .

Add:

And we have: .

. . . . Hence: .