f(x)=3x^2+2x+9 to [3 2 9]

Hello

How can I transform the formula f(x) to a array notation? (x is a symbol)

f(x)=3x^2+2x+9 to [3 2 9]

Thanks in advance

Answer 1

[Wayne King]

syms x;
y = 3*x^2+2*x+9
coeffs(y)

That gives you the coefficients ordered from lowest power of x to the highest.

Or is this not a symbolic computation. Is x a vector?

Wayne

[JR]

Ok, thank you. It only returns the values in the wrong order. (x^2 as last)

[Wayne King]

Exactly, that's what I said -- lowest power of x to the highest.

Answer 2

[Walter Roberson]

http://www.mathworks.com/help/toolbox/symbolic/sym2poly.html

This will be in the order of the highest degree term to the lowest.