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sp2606 [1]
3 years ago
12

Using the quadratic formula to solve 2x2 = 4x – 7, what are the values of x? 2 plus-or-minus StartRoot 10 EndRoot i 1 plus-or-mi

nus StartRoot 10 EndRoot i StartFraction 2 plus-or-minus StartRoot 10 EndRoot i Over 2 EndFraction 1 plus-or-minus StartRoot 5 EndRoot i

Mathematics
2 answers:
grigory [225]3 years ago
8 0

Answer:

C. (Check Attached image)

Step-by-step explanation:

I'm too lasy to explain but to summarize,

- add -2x^2 to both sides

- then plug the numbers into the right places

(Google quadratic formula if you don't remember)

- solve

This post was made by the quadratic Formula gang because factoring is lame.

ioda3 years ago
7 0

Answer:

x = 1 +/- \frac{i\sqrt{10} }{2}

Step-by-step explanation:

The equation given is:

2x^2 = 4x - 7\\\\2x^2 - 4x + 7 = 0

Using quadratic formula:

x = \frac{-b +/- \sqrt{b^2 - 4ac} }{2a}

From the question:

a = 2, b = -4, c = 7

Therefore:

x = \frac{4 +/- \sqrt{(-4)^2 - 4 * 2 * 7} }{2 * 2}\\\\x = \frac{4 +/- \sqrt{(16 - 56)} }{4}\\\\x = \frac{4 +/- \sqrt{-40} }{4}\\

=> x = 1 +/- \frac{i\sqrt{10} }{2}

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4) The path of a satellite orbiting the earth causes it to pass directly over two
Naily [24]

Answers:

  • Satellite is approximately <u>2446.43 km</u> from station A.
  • Satellite is approximately <u>2441.61 km</u> above the ground.

=========================================================

Explanation:

I'm assuming tracking stations A and B are at the same elevation and are on flat ground. In reality, this is likely not the case; however, for the sake of simplicity, we'll assume this is the case.

The diagram is shown below. Points A and B describe the two stations, while point C is the satellite's location. Point D is on the ground directly below the satellite. We have these lengths

  • AB = 60 km
  • AD = x
  • CD = h

Focusing on triangle ACD, we can apply the tangent rule to isolate h.

tan(angle) = opposite/adjacent

tan(A) = CD/AD

tan(86.4) = h/x

x*tan(86.4) = h

h = x*tan(86.4)

We'll use this later in the substitution below.

--------------------

Now move onto triangle BCD. For the reference angle B = 85, we can use the tangent rule to say

tan(angle) = opposite/adjacent

tan(B) = CD/DB

tan(B) = CD/(DA+AB)

tan(85) = h/(x+60)

tan(85)*(x+60) = h

tan(85)*(x+60) = x*tan(86.4) .............  apply substitution; isolate x

x*tan(85)+60*tan(85) = x*tan(86.4)

60*tan(85) = x*tan(86.4)-x*tan(85)

60*tan(85) = x*(tan(86.4)-tan(85))

x*(tan(86.4)-tan(85)) = 60*tan(85)

x = 60*tan(85)/(tan(86.4)-tan(85))

x = 153.612786190499

--------------------

We'll use this approximate x value to find h

h = x*tan(86.4)

h = 153.612786190499*tan(86.4)

h = 2441.60531869599

h = 2441.61 km  is how high the satellite is above the ground.

Return to triangle ACD. We'll use the cosine rule to determine the length of the hypotenuse AC

cos(angle) = adjacent/hypotenuse

cos(A) = AD/AC

cos(86.4) = x/AC

cos(86.4) = 153.612786190499/AC

AC*cos(86.4) = 153.612786190499

AC = 153.612786190499/cos(86.4)

AC = 2446.43279498247

AC = 2446.43 km is the distance from the satellite to station A.

6 0
3 years ago
Celine and Arlene shared $400. Celine received $50 more than Arlene. How much money did Arlene receive?
Lostsunrise [7]

Answer:

Arlene had 175 and Celine had 225

Step-by-step explanation:

5 0
3 years ago
How to find the point-slope form for the slope of 6 and passing through(-7,1)​
MariettaO [177]

Answer: y-1=6(x+7)

Step-by-step explanation:

The formula for point-slope form is y-y_1=m(x-x_1). Since we are given the point and slope, we can directly plug them in.

y-1=6(x-(-7))            [distribute by -1]

y-1=6(x+7)

Now, we know that the point-slope form is y-1=6(x+7).

8 0
3 years ago
Help please!!! No bots!!!!
Slav-nsk [51]

Answer:

Step-by-step explanation:

it's passing thur  quad I  and III  

4 0
3 years ago
Read 2 more answers
If 15 pen cost $3.90, which equation would help determine the cost of 6 pens?
madreJ [45]

Answer

1.56

Step-by-step explanation:

You must find the unit rate. To do so, you must divide 3.90 by 15. That will give you 0.26. After, times 6 and .26 to get your answer. Hope this helps.

8 0
3 years ago
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