03.03.2014 Views

Numerical Methods Course Notes Version 0.1 (UCSD Math 174, Fall ...

Numerical Methods Course Notes Version 0.1 (UCSD Math 174, Fall ...

Numerical Methods Course Notes Version 0.1 (UCSD Math 174, Fall ...

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

154 APPENDIX A. OLD EXAMS<br />

P3 (20 pnts) Let<br />

F = { f(x) = c 0<br />

√ x + c1 l(x) + c 2 e x | c 0 , c 1 , c 2 ∈ R } ,<br />

where l(x) is some black box function. We are concerned with finding the least-squares best<br />

f ∈ F to approximate the data<br />

x 0 x 1 . . . x n<br />

y 0 y 1 . . . y n<br />

(a) Set up (but do not attempt to solve) the normal equations to find the the vector c =<br />

[c 0 c 1 c 2 ] ⊤ , which determines the least squares approximant in F.<br />

(b) Now suppose that the function l(x) happens to be the Lagrange Polynomial associated<br />

with x 7 , among the values x 0 , x 1 , . . . , x n . That is, l(x j ) = δ j7 . Prove that f(x 7 ) = y 7 ,<br />

where f is the least squares best approximant to the data.<br />

P4 (10 pnts) State some substantive question which you thought might appear on this exam, but<br />

did not. Answer this question (correctly).

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!