Year 12s: what will be the first way you research your future options? >>

Remainder theorem - Core 1

ruby_zara

How to you divide x^3 + cx^2 + dx + 3 by x+3, I just don't get it :frown:

.
Thanks

Reply 1

the bear

are you just trying to find the remainder ? if so there is a quick way without dividing.

Reply 2

ruby_zara

They give you the remainder as 65 and you have to write another equation for c and d. (the first one you are given in 3c-d=8

Reply 3

funky2722

Original post by ruby_zara

How to you divide x^3 + cx^2 + dx + 3 by x+3, I just don't get it :frown:

.
Thanks

sub f(-3)=65 you do this because if the equation can be divided by x+3, it means when x=-3, you get the remainder. check google for a better explanation. After u get this equation siumultaneously solve it. And sub in the values to get d and c. Good luck and good night.