# remainder

• September 12th 2009, 08:01 AM
kasia.ogor
remainder
the remainder obtained when $2x^3 + ax^2 - 6x + 1$ is divided by $(x+2)$ is twice the remainder obtained when the same expression is divided by $(x-1)$. Find the value of $a$.
• September 12th 2009, 10:11 AM
red_dog
Let $P(x)=2x^3+ax^2-6x+1$

The remainder when dividing by $x+2$ is $P(-2)$

The remainder when dividing by $x-1$ is $P(1)$

Then we have $P(-2)=2P(1)$

Now find a.