Find the expression for velocity and acceleration of the object

The position of the oscillating object in cm, relative to a fixed point is given as a function of time, t, in seconds by:

a) Find an expression for the velocity and acceleration of the object. (Remember velocity is the derivative of position, and acceleration is the derivative of velocity)

I don't have a lot of experience with physics at all so I'm really unsure about how I should approach this. I tried getting the derivative of the position as the hint suggests, but the answer I got was 0 because I was deriving a constant which can't be right.

• So you take the derivative of the position against time – Yujie Zha May 17 '18 at 4:09
• I tried to do that... or at least I thought I did. I tried to differentiate position and I ended up with -sin(0) which became 0. Any hints? Also I prematurely sent a comment earlier which I deleted in case you were wondering. – bundt tin May 17 '18 at 4:13
• HINT: what's $\frac{d}{dt}\cos(2\pi \omega t)$?, Notice $t$ is NOT a constant – Yujie Zha May 17 '18 at 4:15
• I FEEL SO SILLY THANK YOU SO MUCH!!!! – bundt tin May 17 '18 at 4:16
• No worries, you're welcome – Yujie Zha May 17 '18 at 4:17