Find the values of a and b so that the polynomial (x3-10x2+ax+b) is ex...
Solution:Given: The polynomial (x3 - 10x2 + ax + b) is exactly divisible by (x - 1) and (x - 2).
Step 1: Find the Remainder When Dividing by (x - 1)When a polynomial is divided by x - a, the remainder is the value of the polynomial when x = a. So, to find the remainder when dividing (x3 - 10x2 + ax + b) by (x - 1), we substitute x = 1:
R(1) = (13 - 10a + b)
Therefore, (x - 1) divides (x3 - 10x2 + ax + b) if and only if R(1) = 0.
Step 2: Find the Remainder When Dividing by (x - 2)Similarly, to find the remainder when dividing (x3 - 10x2 + ax + b) by (x - 2), we substitute x = 2:
R(2) = (2a + 2b - 28)
Therefore, (x - 2) divides (x3 - 10x2 + ax + b) if and only if R(2) = 0.
Step 3: Set Up and Solve EquationsTo satisfy the conditions of the problem, we need to find values of a and b such that:
Substituting the expressions for R(1) and R(2) from steps 1 and 2, we get:
- 13 - 10a + b = 0
- 2a + 2b - 28 = 0
Solving these two equations simultaneously, we get:
Therefore, the values of a and b that satisfy the conditions of the problem are a = 9 and b = -4.