I have a sine function y = a*sin(bx-c)+d and I have 4 points on the function: P1(0.840,0.730) P2(1.516,0.594) P3(2.879,0.236) P4(3.365,0.652)?

So I get the following equations:

0.730=a*sin(0.840b-c)+d

0.594=a*sin(1.516b-c)+d

0.236=a*sin(2.879b-c)+d

0.652=a*sin(3.365b-c)+d

Could someone please help me solve for the variables a,b,c,d? Thank you!

Answer 1

[Torsten]

I get

a=-0.386091187

b=-2.36473575

c=-0.96663067

d=0.401059696

Of course, since sin(x)=sin(x+2*Pi), the constant c can be changed to c+2*Pi, c-2*Pi, c+4*Pi, c-4*pi etc.

Best wishes

Torsten.

[Julianna]

Thank you! Have a good day/night! :-)