Algebra
Undetermined coefficients
1. Find a, b, c and d given ax3 + bx2 + cx + d = 7x3 – 10x2 – 3x – 12.
Solution: ax3 + bx2 + cx + d = 7x3 – 10x2 – 3x – 12.
a = 7, b = 10 , c = 3 , d = 12
2. If ( x + m)2 x2 + px + 9, Find m and p.
Solution:
(x + m) 2 x2 + px + 9
x2 + 2mx + m2 = x2 + px + 9
m2 = 9
m = 3
2m = p
p = 6
3. Given (2A +B) x + (A + B) 11x + 7, find the values of A and B.
Solution:
(2A + B)x + (A + B) 11x + 7
2A + B = 11 -----(1)
A + B = 7 -----(2)
Subtract, A = 4
(2) B = 3
