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Amplitude and angular frequency involving Sine waves Watch

1. I've got two questions :/. I've got the answers to them both but i'm just confused about the steps you have to take to get to those answers

1) Express 2sin3t + 6cos3t in the form Acos(wt+a) , a>0

2) A Signal varies in time according to the saw s(t)=3sin(2t)+2cos(2t). Use a suitable trigonometric identity to show that this is actually a sinusoidal signal of the Acos(wt-a) and calculate its maximum value.
The "w" i used is actually omega

Edit: I've figured them both out
2. Get you started on question 1.

You can consider using the R-formulae:

Asin f(t) + Bcos f(t) = R cos[ f(t) - θ ] , where R =sqrt ( A^2 +B^2) and θ =arctan (A/B)

Hope this helps. Peace.
3. (Original post by WhiteGroupMaths)
Get you started on question 1.

You can consider using the R-formulae:

Asin f(t) + Bcos f(t) = R cos[ f(t) - θ ] , where R =sqrt ( A^2 +B^2) and θ =arctan (A/B)

Hope this helps. Peace.
It turned out that the place where i was getting my answer was wrong :/
I figured it out though .
Ty for your input, much appreciated .
4. No problem. Peace.

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