Have you ever wondered if there's a quick way to find the remainder of a polynomial division without performing long division or the lengthy Horner's method? The answer lies in the Remainder Theorem!
The Remainder Theorem provides an interesting relationship between the remainder of a polynomial division and the value of the polynomial itself.
According to the Remainder Theorem, the remainder when P(x) is divided by x−(−4) is P(−4).
Let's calculate P(−4):
P(−4)=2(−4)5+5(−4)4−10(−4)3+9(−4)2−10
P(−4)=2(−1024)+5(256)−10(−64)+9(16)−10
P(−4)=−2048+1280+640+144−10
P(−4)=−2048+1920+144−10
P(−4)=−128+144−10
P(−4)=16−10
P(−4)=6
The result is the same! Using the Remainder Theorem, we found the remainder is 6, just like with Horner's method, but without performing the full division process.
This shows that evaluating P(c) is another way to find the remainder of division by (x−c).