Math 170B HW #5 Partial Solutions ================================= 1. C = (e^(1.3))*(0.00211261)/6 = 0.00129197. 2. C = 1/400. 3. Need n >= 224. 4. f[x_0] = 1, f[x_1] = 3, f[x_0, x_1] = 5. 5a. Computational. 5b. By looking at the table, some of the terms become 0 and the Lagrange interpolatory polynomial has degree 3 (not 5). 6. By reordering the terms nicely, one gets the polynomial to be 5 - (x - 4) - 2(x - 4)(x - 3) + 3(x - 4)(x - 3)(x - 6). 7a. Plug into the formulas and simplify. 7b. Plug into the formulas and simplify. 8a. -1 + (x + 2) - 3(x + 2)(x) = -3x^2 - 5x + 1. 8b. -1 + (x + 2) - 3(x + 2)(x) + (x + 2)(x)(x + 1) = x^3 - 3x + 1. (the point here is that when adding a data point, we don't have to start all over in computing the polynomial - we simply just add one more term) 8c. -3/8 and -9/4, respectively. 9. See the proof of Thm 3.3 on page 108. 10. MATLAB.