The polynomial x3+ 3x2 - 3, 2x3 - 5x + a leave the same remainder in each cases. When divide by x-4 . Find the value of a
Let f(x)=ax³+3x²-3
x-4 leaves a remainder 'p' when divided by p(x);
{x-4 = 0 means at x=4 the polynomial gives a reminder 'p'}
Hence
f(4)=p
So apply 4 to x in f(x),
64a+48-3 =p
64a+45=p ------->(1)
Let g(x)=2x³-5x+a
x-4 leaves a remainder 'q' when divided by g(x);
Hence
g(4)=q
So,
128-20+a=q
108+a=q ------>(2)
It is given that p=q
Equating equation 1 and equation 2,
64a+45=108+a
63a=63
a=1
So the value of 'a' is 1