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2 years ago

Find the value of k such that lim-->4 (x^2+x-k)/(x-4) exists

Mathematics

1 answer:

7nadin3 [17]2 years ago

6 0

Answer:

k=20

Step-by-step explanation:

when x approaches 4, the denominator x-4 approaches 0

if the denominator is 0, it means that this is invalid

if the function is a number over 0 when x=4, it represents a vertical asymptote, which means no limit

so the only way possible to let there be a limit is to let the function be 0/0 when we plug in x=4

so x^2 + x - k = 0 when x = 4

4^2 + 4 - k = 0 ==> 20 - k = 0 ==> k = 20

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-8=-(x+4). Please help I don't know the answer or steps to solve this equation.

Ne4ueva [31]

Answer:

x = 4

Step-by-step explanation:

First u need to distribute the -1 to (x + 4), creating the equation, -8 = -x - 4. Then add the -4 to both sides, and you get, -4 = -x. Then divide by -1 to both sides, and x = 4.

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3 years ago

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Identify the restrictions on the domain of f(x) = quantity x plus 5 over quantity x minus 2. x ≠ 5 x ≠ −5 x ≠ 2 x ≠ −2

horsena [70]

Answer: Third option.

Step-by-step explanation:

By definition, Rational Functions have the following form:

$f(x)=\frac{P(x)}{Q(x)}$

Where $P(x)$ and $Q(x)$ are polynomials.

The Restrictions of the Domain of Rational Functions are those Real numbers that make the denominator equal to zero, because the division by zero is not defined.

In this case, you have the following Rational Function:

$f(x)=\frac{x+5}{x-2}$

The Restrictions of the Domain can be found applying this steps:

- Make the denominator equal to 0:

$x-2=0$

- Solve for "x":

$x=2$

Then, the Domain of this function includes all "x" not equal to 2.

Therefore, the answer is:

$x\neq 2$

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3 years ago

A mixture of paint calls for 1/3 of a cup of red paint and 2/3 cups of yellow paint. How many cups of red paint would be needed

garik1379 [7]

Answer:

Step-by-step explanation:

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3 years ago

Find the mean of the data set: 8, 6, 4.

White raven [17]

Mean = Sum / number

Mean = (8 + 6 +4) / 3

= 18 / 3

= 6

Mean = 6

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3 years ago

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Will mark brainliest! Questions are in the picture!

alexdok [17]

Answer:

52.9 inches .

Step-by-step explanation:

Given that the triangular indentation has an area of 100 in.² and the base and height of this traingle are represented by expressions 3x and x+3 respectively . We need to find out the perimeter to the nearest tenth.

As we know that the area of triangle is ,

$\rm\longrightarrow Area_{\triangle}=\dfrac{1}{2}(base)(height)$

Substituting the respective values,

$\rm\longrightarrow 100\ =\dfrac{1}{2}(x+3)(3x)\\\\\rm\longrightarrow 2(100) = 3x(x+3)\\\\\rm\longrightarrow200 = 3x^2+9x\\\\\rm\longrightarrow 3x^2+9x-200=0$

On using the Quadratic formula , we have;

$\rm\longrightarrow x =\dfrac{-9\pm\sqrt{9^2-4(3)(-200)}}{2(3)} \\\\\rm\longrightarrow x =\dfrac{-9\pm \sqrt{81+1200}}{6}\\\\\rm\longrightarrow x =\dfrac{-9\pm \sqrt{1281}}{6}$