Answers>Maths>IB>Article

When the polynomial 3x^3 +ax+ b is divided by x−2 , the remainder is 2, and when divided by x +1 , it is 5. Find the value of a and the value of b.

Insert the negative values of the divisors and put them into the polynomial. x-2 -> P(2) = 34+2a+b=2   x+1 -> P(-1)=3(-1)+(-1)a+b=5.  22+2a+b=0 -8-a+b=0, then solve the simultaneous equations and obtain the answer: a=-10, b=-2.

ES

Related Maths IB answers

All answers ▸

what is the geometrical meaning of the derivative of a function f?


Given that y = -16x2​​​​​​​ + 160x - 256, find the value of x giving the maximum value of y, and hence give this maximum value of y.


The normal to the curve x*(e^-y) + e^y = 1 + x, at the point (c,lnc), has a y-intercept c^2 + 1. Determine the value of c.


Derive the following: f(x)=(96/x^2)+kx