All categories

2 years ago

Which of the following is an x intercept of the function f(x)=x^2-81?

Mathematics

2 answers:

Anuta_ua [19.1K]2 years ago

7 0

Answer:

The correct option is C.

Step-by-step explanation:

The given function is

$f(x)=x^2-81$

Equate the given function equal to zero, to find the x-intercepts of the function.

$f(x)=0$

$x^2-81=0$

Add 81 both the sides.

$x^2=81$

Taking square root both the sides.

$x=\pm \sqrt{81}$

$x=\pm 9$

The x-intercepts of the given function are -9 and 9. Therefore the correct option is C.

Doss [256]2 years ago

4 0

<span>x intercept when f(x) = 0
so
</span><span>x^2-81 = 0
x^2 = 81
x = + 9 and x = -9

Answer
</span><span>C -9</span>

You might be interested in

Help me solve this problem please

ICE Princess25 [194]

Answer:

actually what is this is you is this a geometry, trigonometry I don't know what to call

8 0

2 years ago

7x-4y=-7 5x+y=22 please show work

Keith_Richards [23]

What exactly are you finding

3 0

3 years ago

The coordinates triangle ABC are A (0, 2), B (-2, 6), and C (4, 0). Find the slope of BC.

salantis [7]

In the given triangle, the slope of line BC is (C) -1.

<h3>What is the slope?</h3>

In mathematics, a line's slope, also known as its gradient, is a numerical representation of the line's steepness and direction.

A line's slope is how steeply it slopes from LEFT to RIGHT.

The slope of a line is determined by dividing its rise, or vertical change, by its run, or horizontal change.

No matter which two locations on the line you choose, the slope of a line is always constant (it never varies).

So, the slope of line BC:

Coordinates of BC are:

B: (-2, 6)

C: (4, 0)

Slope formula: m = y2-y1/x2-x1

Now, substitute the values and calculate as follows:

m = y2-y1/x2-x1

m = 0-6/4-(-2)

m = -6/6

m = -1

Therefore, in the given triangle, the slope of line BC is (C) -1.

Know more about slopes here:

brainly.com/question/29280886

#SPJ1

8 0

1 year ago

The U.S. and many other countries have recently tightened airport security. A sociologist is interested in estimating the propor

melisa1 [442]

Answer:

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

Step-by-step explanation:

Conduct a test to determine whether the true proportion of interest is higher than 0.7.

This means that the null hypothesis is: $H_{0}: p = 0.7$

And the alternate hypothesis is: $H_{a}: p > 0.7$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.7 is tested at the null hypothesis:

This means that $\mu = 0.7, \sigma = \sqrt{0.7*0.3}$

The sociologist found that 375 of the 500 travelers randomly selected and interviewed indicated that the airports were safe.

This means that $n = 500, X = \frac{375}{500} = 0.75$

Value of the z-statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.75 - 0.7}{\frac{\sqrt{0.7*0.3}}{\sqrt{350}}}$

$z = 2.44$

P-value of the test:

Probability of z being larger than 2.44, that is, a proportion larger than 0.75.

This is, looking at the z-table, 1 subtracted by the pvalue of Z = 2.44. S

Z = 2.44 has a pvalue of 0.9927

1 - 0.9927 = 0.0073

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

8 0

3 years ago

I need your help ASAP!

slega [8]

Answer:

Step-by-step explanation:

If 4ab+k=13 then k=13-4ab

8 0

2 years ago