When you are replying to a message, remember to quote enough of the original
message to put your new contribution into context.
In this case, your original question was:
I currently have a set of data for a pendelum, resembeling a sin function.
What functions or equations in excell can I use to find the sin function
representing this pendelum using my data?
One option is to put your data values in column B. Put a set of dependent
variables in column A, say 0 to 21 in your case.
You could then put a sine wave equation in say column F, using a formula
=C$24*SIN(PI()*(A1-D$24)/E$24), using constants in C24:E24.
You can put an error squared term in column G, with the formula =(F1-B1)^2,
and then sum the error squared terms with =SUM(G1:G22)
You can then use Tools/ Solver to minimise this last term by changing
C24:E24, but you may need a reasonable guess at the values initially to
allow it to converge, so you'll probably need to look at the form of the
data to guess those initial values.
It's probably useful to plot the original data and your sine-wave
approximation together on a chart to see how well you've done.
