Answer:
a + b + c + d = 0
Explanation:
To determine the sum of a, b, c and d, first find the values of a, b, c and d using the given information.
The given rational function is:


Value of a
Given:

Evaluate h(x) at x = -1/2:

As the limit of h(x) as x approaches -1/2 is an indeterminate form of 0/0, and the numerator and denominator are both differentiable, we can use L'Hôpital's rule to evaluate the limit.
By L'Hôpital's rule:

Therefore:

Substitute x = -1/2 into the differentiated numerator and denominator:

Therefore, the value of a is:


Value of b
Given h(0) = b, we can find the value of b by substituting x = 0 into the function:

Therefore, since h(0) = 0, then the value of b is:


Value of c
The vertical asymptote of a rational function occurs where the denominator equals zero.
Given that the vertical asymptote of h(x) is at x = c, to find the value of c, set the denominator of h(x) equal to zero and solve for x.
First, factor the numerator and denominator:

Cancel the common factor (2x + 1):

Now, set the denominator equal to zero and solve for x:

Therefore, since x = c, then the value of c is:


Value of d
We are given that as x approaches infinity, h(x) = d:

Divide both the numerator and denominator by the highest power of x, which is x²:


As x approaches infinity, the terms with 1/x and 1/x² become negligible:

Therefore, the value of d is:


Sum of a, b, c and d
To find the sum of a, b, c and d, simply add together the found values of a, b, c and d:

Therefore, the sum of a, b, c and d is zero.
