My first Script (polynomials)

[dishes]

I need to make a function that differentiates a polynomial. It needs to be in the form: function dy = differ(a, x), where a is a vector of any length representing the coefficients of the polynomial, and x is a vector of any length giving the points at which the derivative is evaluated.

For example, if a = [2 4 7 3 4], it would be 2x^4 + 4x^3 + 7x^2 + 3x + 4.
And say x = [1 2 4 5]. The program should take a and differentiate it (in this case giving 8x^3 + 12x^2 + 14x + 3) and then apply it to the values in the vector x. So this input would return 37, 143, 763, 1373.

Another example, if a = [1 2 0 1] (meaning 1x^3 + 2x^2 + 1 which is differentiated to 3x^2 + 4x) and x = [1 2 3], then the output would be 7, 20, 39.

I cannot use existing matlab functions here. Does anyone know how i would go about making this function? Thanks.

[the cyclist]

dishes <fartybar...@hotmail.com> wrote in message <1035469021.125241.1256...@gallium.mathforum.org>...

Everything you have said here points to this being a homework problem. People here are more inclined to give homework hints when the student first exhibits some genuine effort at having solved it themselves.

the cyclist

[dishes]

ok I think im on a role atm, but i will prob need you guys help later ^^