Function Description
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	Name: SINU_2 
	Function: f(x) =  a0 * cos(a1*x+a2) + a3 
	Parameters: a0 a1 a2 a3

Notes
*****

With 4 parameters, it is hard to get convergence. Try holding the A1
parameter constant. TO_RAD converts degree measurements to radians.

C-code for the function
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	 b = fabs(x-60.0)*TO_RAD;
	 answer = a0 * cos(a1 * b + a2) + a3;