Advertisements
Advertisements
Question
If x − 3 is a factor of x2 − ax − 15, then a =
Options
-2
5
-5
3
Advertisements
Solution
As (x -3) is a factor of polynomial f(x) = x2 − ax − 15.
i.e. f(3) = 0
Therefore,
`(3)^2 - a(3) -15 = 0`
`9-3a - 15 = 0`
`a = -2`
APPEARS IN
RELATED QUESTIONS
In each of the following, using the remainder theorem, find the remainder when f(x) is divided by g(x) and verify the result by actual division: (1−8)
f(x) = x3 + 4x2 − 3x + 10, g(x) = x + 4
If x − 2 is a factor of the following two polynomials, find the values of a in each case x3 − 2ax2 + ax − 1.
x4 + 10x3 + 35x2 + 50x + 24
If \[x = \frac{1}{2}\] is a zero of the polynomial f(x) = 8x3 + ax2 − 4x + 2, find the value of a.
If x + a is a factor of x4 − a2x2 + 3x − 6a, then a =
The value of k for which x − 1 is a factor of 4x3 + 3x2 − 4x + k, is
Factorise the following:
y2 – 16y – 80
Factorise the following:
m2 + 2mn – 24n2
If (x + 5) and (x – 3) are the factors of ax2 + bx + c, then values of a, b and c are
Factorise:
x3 – 6x2 + 11x – 6
