page 70
 
PREVIOUS PAGE COVER PAGE TABLE OF CONTENTS INDEX ANSWERS TO ODD NUMBERED PROBLEMS NEXT PAGE
 

31. Letbe defined as in Problem 30 above and show:
(a) if f(x) is a polynomial of degree less than n.
(b) if f(x) = a0xn + a1xn -1 + ... + an.

32. Let f(x) = a + bx + cx2. Let r = f(0), s = f(1) - f(0), and t = f(2) - 2f(1) + f(0).

(a) Show that f(x) = r + sx + tx(x - 1)/2.

(b) Generalize this problem.

33. Let f(x) = 5x4 - 6x3 - 3x2 + 8x + 2. Use repeated synthetic division to find numbers a, b, c, d, and e such that
 

f(x) = a + b(x - 2) + c(x - 2)2 + d(x - 2)3 + e(x - 2)4.

34. Use the method of the alternate solution for Example 3 in Section 8.1 to do Problem 33.

35. Let f(x) = x3 + ax2 + bx + c, and let a, b, c, and r be complex numbers. Show that
 

f(x) = f(r) + (3r2 + 2ar + b)(x - r) + s(x - r)2 + (x - r)3,

and express s in terms of a and r.

36. Let f(x) = x3 + ax2 + bx + c, and let r be a root of f(x) = 0. Show that f(x) is divisible by
(x - r)2 if and only if 3r2 + 2ar + b = 0.  [If m is an integer greater than 1 and a polynomial f(x) is divisible by (x - r)m but not by (x - r)m+1, we say that r is a multiple root of f(x) = 0 with multiplicity m.]

37. Let f(x) = x3 + ax2 + bx + c, g(x) = 3x2 + 2ax + b, and h(x) = 6x + 2a. Show that
f(x) = (x - r)3 if and only if f(r) = g(r) = h(r) = 0.

38. Let f(x) = x4 + ax3 + bx2 + cx + d. Find s, t, and u in terms of a, b, c, and r such that
 

f(x) = f(r) + s(x -r) + t(x - r)2 + u(x - r)3 + (x - r)4.

39. Do the methods of this chapter enable you to solve x3 - 3x + 1 = 0?
 
 

PREVIOUS PAGE COVER PAGE TABLE OF CONTENTS INDEX ANSWERS TO ODD NUMBERED PROBLEMS NEXT PAGE
 
page 70
Friday, May 15, 1998