If f(x)=x+4x2+ax+b and f(x) has two vertical asymptotes at x=1 and x=−2, find the sum of a and b.
x + 4
__________
x^2 + ax + b
If the vertical asymptotes are x =1 and x = -2....the denominator is
( x - 1) ( x + 2) = x^2 + x - 2
So.....
a = 1 and b = -2
So....a + b = 1 + (-2) = -1