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Help with this one please​

Help with this one please​-example-1
User Pablito
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1 Answer

4 votes

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:


h(x)=(6x^2+3x)/(2x^2+5x+2)


\hrulefill

Value of a

Given:


\displaystyle \lim_{x \to -(1)/(2)}h(x)=a

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


h\left(-(1)/(2)\right)=(6\left(-(1)/(2)\right)^2+3\left(-(1)/(2)\right))/(2\left(-(1)/(2)\right)^2+5\left(-(1)/(2)\right)+2)=(0)/(0)

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:


\displaystyle \lim_(x \to a)(f(x))/(g(x))&=\lim_(x \to a)(f'(x))/(g'(x))

Therefore:


\displaystyle \lim_{x \to -(1)/(2)}(6x^2+3x)/(2x^2+5x+2)&=\lim_{x \to -(1)/(2)} (12x+3)/(4x+5)

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


\displaystyle \lim_{x \to -(1)/(2)}(6x^2+3x)/(2x^2+5x+2)&=\lim_{x \to -(1)/(2)} (12x+3)/(4x+5)=(12\left(-(1)/(2)\right)+3)/(4\left(-(1)/(2)\right)+5)=(-3)/(3)=-1

Therefore, the value of a is:


\Large\boxed{\boxed{a=-1}}


\hrulefill

Value of b

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


h(0)=(6(0)^2+3(0))/(2(0)^2+5(0)+2)=(0)/(2)=0

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


\Large\boxed{\boxed{b = 0}}


\hrulefill

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:


h(x)=(3x(2x+1))/((2x+1)(x+2))

Cancel the common factor (2x + 1):


h(x)=(3x)/(x+2)

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


x+2=0 \implies x=-2

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


\Large\boxed{\boxed{c=-2}}


\hrulefill

Value of d

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


\displaystyle \lim_(x \to \infty)(6x^2+3x)/(2x^2+5x+2)=d

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


\displaystyle \lim_(x \to \infty)((6x^2)/(x^2)+(3x)/(x^2))/((2x^2)/(x^2)+(5x)/(x^2)+(2)/(x^2))=d


\displaystyle \lim_(x \to \infty)(6+(3)/(x))/(2+(5)/(x)+(2)/(x^2))=d

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


d=(6+0)/(2+0+0)=(6)/(2)=3

Therefore, the value of d is:


\Large\boxed{\boxed{d=3}}


\hrulefill

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:


\begin{aligned}a+b+c+d&=(-1)+0+(-2)+3\\&=-1+0-2+3\\&=-1-2+3\\&=-3+3\\&=0\end{aligned}

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


\Large\boxed{\boxed{a+b+c+d=0}}

User Shawn K
by
7.3k points