simple harmonic motion help

[General_Thral]

heya ive got a few questions from ym physics teacher , and i have no idea how im spose to go about starting them . ok the first question:

(a) X= 3.2x10^-3 20cost

and from that ive got to deduce the amplitude of the motion

(b) the frequency of the motion.

the help is very much apreciated .

[Sphere]

Damn, thought I had repressed that stuff.

Amplitude is the difference between the max and min values of the function. Since cos(t) will vary between -1 and 1 you get

3.2e-3 * 20(-1) = -.064
3.2e-3 * 20(1) = .064

Amplitude = .064+.064 = .128

Frequency..hmm..not gonna cheat and use wiki here, so take this with a grain of salt.

One cycle should take 2π seconds (same as 360 degrees) as it is simply cos(t) which is...

Frequency = 6.3 Hertz.

If you bring up damped harmonic motion I might need physicatric help.