Question 302 of 455MediumMCQ
Let p(x) be a quadratic polynomial such that p(0)=1. If p(x) leaves remainder 4 when divided by x−1, and remainder 6 when divided by x+1, then Solutions · 1
Official solution
Let, P(x) = ax2 + bx + c
As, P(0) = 1,
\[\therefore\,\,\,\] a(0)2 + b(0) + c = 1
\[ \Rightarrow \] c = 1\therefore\,\,\,\[ P(x) = ax2 + bx + 1
If P(x) is divided by x \]-1, remainder = 4⇒\[\,\,\,\] P\[\left( 1 \right) = 4\]
\[\therefore\,\,\,\] a + b + 1 = 4 . . . . . (1)
If P(x) is divided by x + 1, remainder = 6
\[ \Rightarrow \] P(−1) = 6∴a-\[ b + 1 = 6 . . . .(2)
By solving (1) and (2) we get,
a = 4, and b = \]-1∴P(x) = 4x2−x + 1
P(2) = 4(2)2−2 + 1 = 15
P(−2) = 4 (−2)2−(− Answer the question to unlock