Mathematics
What must be subtracted from the polynomial x3 + x2 - 2x + 1, so that the result is exactly divisible by (x - 3)?
Factorisation
3 Likes
Answer
Polynomial : x3 + x2 - 2x + 1
Division by x - 3
⇒ x - 3 = 0
⇒ x = 3.
Let k be subtracted from the polynomial, so resulting polynomial is x3 + x2 - 2x + 1 - k.
Resulting polynomial should be exactly divisible by x - 3,
Thus, substituting x = 3, in polynomial x3 + x2 - 2x + 1 - k, remainder = 0.
⇒ 33 + 32 - 2(3) + 1 - k = 0
⇒ 27 + 9 - 6 + 1 - k = 0
⇒ 31 - k = 0
⇒ k = 31.
Hence, k = 31.
Answered By
1 Like
Related Questions
Find the value of a so that (x + 6) is a factor of the polynomial (x3 + 5x2 - 4x + a).
For what value of a is the polynomial (2x3 + ax2 + 11x + a + 3) exactly divisible by (2x - 1)?
What must be subtracted from 16x3 - 8x2 + 4x + 7 so that the resulting expression has (2x + 1) as a factor?
Using factor theorem, show that (x - 3) is a factor of (x3 - 7x2 + 15x - 9). Hence, factorize the given expression completely.