Trig Modelling

• May 21st 2008, 03:01 AM
Webby
Trig Modelling
A mass on a spring moves up and down with its displacement given by;
x=3-4cos((2pi/5)t). X is in centimetres and t is in seconds.

a)find the inital displacement
b)the displacement after 30 seconds
c)the greatest displacement

Help greatly appreciated in advance :)
• May 21st 2008, 03:16 AM
flyingsquirrel
Hi
Quote:

Originally Posted by Webby
A mass on a spring moves up and down with its displacement given by;
x=3-4cos((2pi/5)t). X is in centimetres and t is in seconds.

a)find the inital displacement

This is $x(0)=3-4\cos\left(\frac{2\pi}{5}\cdot 0\right)= ?$
Quote:

b)the displacement after 30 seconds
This is $x(30)=3-4\cos\left(\frac{2\pi}{5}\cdot 30\right)= ?$
Quote:

c)the greatest displacement
Find the maximum of $x(t)$ using its derivative or the properties of the cosine function.