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4 years ago

Solve and graph the equation x2+x-6=0

Mathematics

1 answer:

eimsori [14]4 years ago

3 0

Y=x²+x-6 (original form ax²+bx+c)

1) this is a parabola open upward since the coefficient of x² is positive
so it has a minimum.

2) Its symmetry line = -b/2a = -1/2 & for x=-1/2, y= 23/4
So its minimum is (-1/2, 23/4)

3) Now to see if the parabole intercepts the x-axis we calculate the roots of
x²+x-6. As you will notice Δ <0 so there is no roots & consequently it doesn't intersect with x-axis
Your graph is wrong, and the parabola should be above the x-axis & it will intersect with the y-axis at y=23/4 =5.75nunits

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Find the measure of the indicated angle<br> (geometry)

zalisa [80]

The little lines through the two sides of the triangle mean the sides are equal length.

Because the sides are equal, the two bottom angles are also the same.

Since angle B is given as 46 degrees, angle C is also 46 degrees.

The three inside angles of a triangle need to equal 180 degrees.

Angle A = 180 - 46 - 46 = 88 degrees.

8 0

4 years ago

Solve the equation.Check your solution.<br> -16=0.2b

ipn [44]

Answer:

b = -80

Step-by-step explanation:

-16 = 0.2b

Divide both sides by 0.2

We have , -16/0.2 = 0.2b/0.2

Therefore, b = -80

3 0

3 years ago

Read 2 more answers

Can anyone plz help me

faltersainse [42]

7.5/18=15/x
Cross multiply
7.5x/270
Divide both sides by 7.5 to get x alonex=36
Hope that helps! :)

3 0

4 years ago

The cost of Internet access. How much do users pay for Internet service? Here are the monthly fees (in dollars) paid by a random

Ivanshal [37]

Answer:

$20.9-2.01\frac{7.65}{\sqrt{50}}=18.73$

$20.9+2.01\frac{7.65}{\sqrt{50}}=23.07$

The 95% confidence interval would be given by (18.73;23.07)

Step-by-step explanation:

Assuming these data

20 40 22 22 21 21 20 10 20 20

20 13 18 50 20 18 15 8 22 25

22 10 20 22 22 21 15 23 30 12

9 20 40 22 29 19 15 20 20 20

20 15 19 21 14 22 21 35 20 22

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Solution to the problem

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

First we need to find the sample mean with the following formula:

$\bar X= \frac{\sum_{i=1}^n X_i}{50}=20.9$

And in order to find the sample standard deviation we can use the following formula:

$s= \sqrt{\frac{\sum_{i=1}^n (x_i -\bar x)^2}{n-1}}=7.65$

In order to calculate the critical value $t_{\alpha/2}$ we need to find first the degrees of freedom, given by:

$df=n-1=50-1=49$

Since the Confidence is 0.95or 95%, the value of $\alpha=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,49)".And we see that $t_{\alpha/2}=2.01$

Now we have everything in order to replace into formula (1):

$20.9-2.01\frac{7.65}{\sqrt{50}}=18.73$

$20.9+2.01\frac{7.65}{\sqrt{50}}=23.07$

So on this case the 95% confidence interval would be given by (18.73;23.07)

8 0

3 years ago

What is the value of x in the <br> triangle?

Makovka662 [10]

Answer:

x = 75°

Step-by-step explanation:

Sum of angles in a triangle: 180°

So,

50°+55°+x=180°

105°+ x = 180°

Subtract 105° from both sides

x = 75°

8 0

3 years ago