f(x) = –3√x, 1 ≤ x ≤ 4 (a) Find the quadratic least squares approximating function g for the function f. g(x)=?
The best fit function is clearly g(x)=-3/sqrt(x). But I'm guessing you trying to fit a function that's doesn't have that form. What kind of function are you trying to fit and what's the definition of 'least squares fit'?
If you could help that would be very much appreciated as I do not knw how to punch and chug that in an intergral.
I think you want to minimize the integral of (f(x)-g(x))^2 don't you? Put in your f(x) and your g(x). It's not a hard integral. Just square it out. It's just powers of x. Then try to minimize with respect to a0, a1 and a2.
Use partial derivatives with respect to a0, a1 and a2. What should they be at a minimum? Didn't they teach you that part?
What should the partial derivatives be at a minimum? Missing the class means i) you could try to find the method yourself by looking it up or reading a book or even better, ii) thinking about it yourself.