Deriving an equation for a spring movement. Sort of understand it but not really :S. Details inside. Please help understand. Thanks!

Question

anonymous · Answer

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anonymous · Answer

So I know it's gonna be a multiplication with either a sine or a cosine function.

anonymous · Answer

I also know that we want it multiplied by a line that gets smalled by 1/4

anonymous · Answer

I'm having a hard time putting these thoughts into a formula.

anonymous · Answer

I dont think you need trig to solve this problem

anonymous · Answer

its a simple linear equation, all you have to pay attention to, is the the time period to decide if you will need either add or subtract to get the length.