Cubic Fit to minimize a polynomial

hi,

using "cubic fit" calculate : min x^4 + 2*x + 4

i need some guidance how to code this?

i have searched and found this formulation for cubic fit

Answer 1

[Walter Roberson]

Use calculus. To find min(f(x)) then solve . The roots of that give you the critical points; call those for the moment. Then, examine . Positive values indicate that the corresponding was a minima.

For a degree 4 polynomial, the derivative is degree 3, and there are closed form solutions for the roots of a polynomial of degree 3. Therefore you can calculate the exact critical points, and test them.

You will only find one real-valued root. You might assume that it must be the minima, but in the general case, it will not be a safe assumption.

[Haris Hameed]

Thank you. i understand it now