The polynomials and
when divided by (x-4) leave the same remainder. Find the value of a.
Let f(x) = ax3 + 3x2 – 3
And,
g(x) = 2x3 - 5x + a
Now,
f(4) = a(4)3 + 3(4)2 – 3
= 64a + 48 - 3
= 64a + 45
And,
g(4) = 2(4)3 – 5(4) + a
= 128 – 20 + a
= 108 + a
According to the question,
f(4) = g(4)
64a + 45 = 108 + a
64a – a = 108 – 45
63a = 63
a = 1
Hence, the value of ‘a’ is 1.