If the polynomials ax3+3x2-13 and 2x3-5x+a when divided by (x-2) leave the same remainder, find the value of a.
Let p (x) = ax3+3x2-13 and q (x) = 2x3-5x+a be the given polynomials.
The remainders when p (x) and q (x) are divided by (x – 2) and p (2) and q (2) respectively.
By the given condition, we have:
p (2) = q (2)
a (2)3 + 3 (2)2 – 13 = 2 (2)3 – 5 (2) + a
8a + 12 – 13 = 16 – 10 + a
7a – 7 = 0
7a = 7
a =
= 1