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3 years ago

Consider the quadratic function f(x)=2x^2-8x-10

Mathematics

1 answer:

Slav-nsk [51]3 years ago

6 0

Answer:

f(x) = 2x² - 8x - 10.

This is a parabola open upward (since a>0) with an axis of symmetry = -b/2a:

a) axis of symmetry: x = -(-8)/(2*2) = 8/4 = 2. Then x = 2, which is the x component of the vertex

b) for x = 2, f(x) = f(2) = - 18 (component of y of the vertex)

c) VERTEX(2, - 18)

d) DISCRIMINENT: b² - 4.a.c = 64 - 4*2*(-10) = 144

Hope this helps! :)

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Please help me on this asap this is very important :D

Anettt [7]

Answer:

78.5

Step-by-step explanation:

area of a circle is $\pi r^{2}$

3.14( $5^{2}$ )=78.5

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3 years ago

Liza gets paid $5.50 an hour to babysit her little cousins. Last weekend, she watched them for three hours on Friday, nine hours

8_murik_8 [283]

Answer: B (104.50)

explanation: 5.5*3=16.5
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2 years ago

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Solve for y. xy + p = 5 A) y = 5 - p - x B) y = (5-p)/x C) y = 5 - px

Damm [24]

Minus p both sides
xy=5-p
divide both sides by x
y=(5-p)/x

B

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2 years ago

What value of x makes the following equation true x + 10 = 18

Mademuasel [1]

X+10=18. |-10 from both sides
x+10-10=18-10
x=8

6 0

2 years ago

Read 2 more answers

An educational psychologist wishes to know the mean number of words a third grader can read per minute.

Rama09 [41]

Answer: 208.

Step-by-step explanation:

The formula to find the minimum sample size is given by :-

$n= (\dfrac{z^*\times \sigma}{E})^2$ (1)

, where z* = critical z-value (two tailed).

$\sigma$ = Standard deviation ( from prior study ) and E = Margin of error.

As per given , we have

Margin of error : E= 0.29

Confidence level = 85%

Significance level = $\alpha=1-0.85=0.15$

Using z-table , the critical value (two -tailed)= $z^*=z_{\alpha/2}=z_{0.15/2}=z_{0.075}=1.439$

As per previous study , Variance = $\sigma^2=8.41$

$\sigma=\sqrt{8.41}=2.9$

Now, the required minimum sample size = $n= (\dfrac{(1.439)\times (2.9)}{0.29})^2$ [Substitute the values in formula (1)]

$n=(14.39)^2$

$n=207.0721\approx208$ [ Round to the next integer]

Hence, the minimum number of third graders that must be included in a sample = 208.

5 0

3 years ago