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Mcfok July 15th, 2015 11:34 AM

Maximum value
 
Find the maximum displacement of the oscillation

x=2cos(wt) +cos[wt-(π /6)]

mathman July 15th, 2015 12:46 PM

Use elementary calculus to get:

let $\displaystyle c=\frac{\pi}{6}$

0=2sin(wt)+sin(wt-c)=2sin(wt)+sin(wt)cos(c)-cos(wt)sin(c)

Let s=sin(wt)

$\displaystyle s(2+cos(c))=\sqrt{1-s^2}sin(c)$

I'll let you finish - square both sides, solve for $\displaystyle s^2$, etc.

v8archie July 15th, 2015 12:46 PM

I think you should start by using $$\cos(A+B) = \cos A \cos B - \sin A \sin B$$ on the second term.


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