When I try and model a curve using a sine regression with my graphic calculator, it returns an error message that says: Singular Matrix(adsbygoogle = window.adsbygoogle || []).push({});

I decided then to do it by hand. Here are three points.

Minimum: (0,554.8), Maximum: (45, 1220.5) and a random point (20, 830.7)

I want something in the format of: A*sin B(x-c) + d

This is what I did, is it correct?

A = (1220.5-554.8)/2

B = (2*pi)/45

D = (1220.5+554.8)/2

C = One unknown, so I used the random point shown to solve:

(Should I have calc in radians or degrees?)

My steps: ( I will use letters for simplicity)

830.7 = A*sinB(x-c)+d

830.7 - D = A*sinB(x-c)

Ans/A = sinB(x-c)

sin^{-1}(Ans/A) = B(x-c)

Ans/B=x-c

-c=(Ans/B)-x

But I am not getting anything sensible...

Is my calculator right or did I do anything wrong?

Thanks

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# Homework Help: Sine Regression

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