I ment "get a curve like". My assignment is to make a function that gives a curve which looks like the curve this function gives 0.00083*x^4-0.09375*x^2+3 in x=-8..8. Now to do that I've chosen to use the function f = a*cos(b*x)+c. And to give the same curve this have to be true a*cos(b*8)+3=0.4 and -a*sin(b*8)*b=0.2. And x has to be x=-8..8.

I ment "get a curve like". My assignment is to make a function that gives a curve which looks like the curve this function gives 0.00083*x^4-0.09375*x^2+3 in x=-8..8. Now to do that I've chosen to use the function f = a*cos(b*x)+c. And to give the same curve this have to be true a*cos(b*8)+3=0.4 and -a*sin(b*8)*b=0.2. And x has to be x=-8..8.

Their should only be 1 solution for a and 1 solution for b. a and b are constants. I have to make a function which makes a graph just like this function  0.00083*x^4-0.09375*x^2+3, x=-8 ..8. to do that I've chosen to use this function f(x)=a*cos(b*x)+3, for which I know that 0.4=a*cos(b*8)+3 and 0.2=-a*sin(b*8)*b. Or is it impossible to get a graph like the one  0.00083*x^4-0.09375*x^2+3, x=-8 ..8 gives, with the a*cos(b*x)+3 function?

Their should only be 1 solution for a and 1 solution for b. a and b are constants. I have to make a function which makes a graph just like this function  0.00083*x^4-0.09375*x^2+3, x=-8 ..8. to do that I've chosen to use this function f(x)=a*cos(b*x)+3, for which I know that 0.4=a*cos(b*8)+3 and 0.2=-a*sin(b*8)*b. Or is it impossible to get a graph like the one  0.00083*x^4-0.09375*x^2+3, x=-8 ..8 gives, with the a*cos(b*x)+3 function?