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Over [174]
3 years ago
12

Solve x2+4x+6=0 by graphing

Mathematics
1 answer:
klemol [59]3 years ago
4 0

Answer: x = -2±√2 i or no real roots. See the explanation below.

Step-by-step explanation:

If you draw the graph, you will notice that there are no common points or you can say that there are no x-intercepts.

This means that the equation doesn't have any real roots.

If there are 2 common points (2 x-intercepts) then there are 2 real roots (answers.)

If there is only one common point (vertex is on x-axis) then there is only 1 real root.

If there aren't any common points (no x-intercepts) then there are no real roots.

So first, I'm gonna convert the equation into function and convert the standard form to vertex form.

x^2+4x+6=0\\y=x^2+4x+6\\y=(x^2+4x+4)-4+6\\y=(x+2)^2+2

We notice that the vertex is at (-2,2), the graph doesn't have x-intercepts (Graph below)

So the answer is clearly complex.

If you solve this by solving the equation then it'll be.

x^2+4x+6=0\\x= \frac{-b+-\sqrt{b^2-4ac}}{2a} \\x=\frac{-4+-\sqrt{16-24} }{2}\\x=\frac{-4+-\sqrt{-8} }{2}\\\\x=\frac{-4+-2\sqrt{2}i }{2}\\\\x={-2+-1\sqrt{2}i }\\\\

The answer is complex.

However, you can find the value of x easily by graphing. For example.

x^2+6x+5=0

Factor then you get

(x+5)(x+1)=0\\x=-5,-1

Or you can convert it to vertex form then graph.

y=x^2+6x+5

y=(x^2+6x+9)-9+5\\y=(x+3)^2-4

The vertex is at (-3,-4) then graph parabola (x-intercepts determine the roots of quadratic equation. For the graph, parabola intercepts x at (-5,0) and (-1,0) that means both -5 and -1 both are the value of x.

Note:

From the standard form, y=ax^2+bx+c The graph is called Parabola, and it's Quadratic Function.

a is how the graph is, for example. If a>0, the graph is supine parabola and if a<0 then the graph is inverted parabola.

|a| is determined if the graph is wide or narrow, the more the value of a is, the more narrow it will be. The less the value of a is, the more wide it will be.

b is what determined the change of graph (likely vertex). Without b, then it'd be ax^2+k which only move y-axis and not x-axis.

c is what determined the y-intercept and y-axis. If there is no b or the value of b is 0 then the vertex is at (0,c). If there is the value of b then c is only determined the y-intercept.

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Oliver interviewed 30% of the 9th grade class and 70% of the 10th grade class at his school. Jenny interviewed 75% of the 9th gr
julia-pushkina [17]

Answer:

A. 36

Step-by-step explanation:

We are given a total of 176 interviewed by Oliver and a total of 140 interviewed by Jenny. To find how many more 10th graders than 9th graders were interviewed, subtract the totals given

176 - 140 = 36

This is how we came to the answer:

We are given 70% of the 10th-grade and 30% of the 9th-grade with a total of 176 for Oliver.

While we're given 75% of the 9th-grade class and 25% of the 10th-grade with a total of 140 interviewed by Jenny

Oliver's Interviewees

10-graders

Firstly, let's find what the number of 9th-graders was interviewed by Oliver; find the percentage of the 9th-graders by the total;

70% of 176 =

Cross multiply

123.2 were 10-graders interviewed by Oliver

9th-graders

Now, to find the number of 9th-graders was interviewed by Oliver; find the percentage of the 9th-graders by the total;

30% of 176 =

 

Cross multiply

52.8 were 9th-graders interviewed by Oliver

Jenny's Interviewees

9th-graders

Firstly, let's find what the number of 9th-graders was interviewed by Jenney; find the percentage of the 9th-graders by the total;

75% of 140 =

 

Cross multiply

105 students were 9th-graders interviewed by Jenney.

10th-graders

Now, to find the number of 10th-graders was interviewed by Jenney; find the percentage of the 10th-graders by the total;

25% of 140 =  

 

Cross multiply  

35 students were 10th-graders interviewed by Jenney.  

Total calculation

Use the results and sum them up by 9th-grade plus 9th-grade and 10th-grade plus 10-grade. Then subtract the amount gotten from 9th-grade away from the amount gotten from 10th-grade;

Oliver's 9th-grade = 52.8

Jenny's 9th-grade = 105

105 + 52.8 = 157.8

Oliver's 10th-grade = 123.2

Jenny's 10th-grade = 35

123.2 + 35 = 158.2

Total calculation: 158. 2 - 157.8 = 0.4

Therefore, there are 36 more 10th than 9th.

For more information, visit: brainly.com/question/23490909

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Ravi made 6 identical necklaces, each having beads and a pendant. The total cost of the beads and pendants for all 6 necklaces w
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Answer: $ 2.20

Step-by-step explanation: 31.80-18.60= 13.20

13.20 divided by 6= 2.20

——————-

2.20 x 6= 13.2

13.20+ 18.60= 31.80

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Help solve the following equation: 20.6 + 2.1x = -8.2x
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20.6 + 2.1x = -8.2x

20.6=-10.3x

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I WILL MARK AS BRAINLIEST! Graph each coordinate pair on the graph and then indicate which quadrant or axis the point lies on.
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Answer:

3 quadrant

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A hypothetical population consists of eight individuals ages 13, 14, 17, 20, 21, 22, 24, &amp; 30 years.
Alika [10]

Complete Question

A hypothetical population consists of eight individuals ages 13 14 17 20 21 22 24 30 years.  

A: what is the probability that a person in this population is a teenager?  

B: what is the probability of selecting a participant who is at least 20 years old?

We have that  probability that a person in this population is a teenager and probability of selecting a participant who is at least 20 years old is

From the question we are told

A hypothetical population consists of eight individuals ages 13, 14, 17, 20, 21, 22, 24, & 30 years.

  • P(T)=0.38
  • P(T')=0.63

a)

Generally the equation for the  probability that a person in this population is a teenager   is mathematically given as

P(T)=\frac{no of teens}{n}\\\\P(T)=\frac{3}{8}

P(T)=0.38

b)

Generally the equation for the probability of selecting a participant who is at least 20 years old  is mathematically given as

P(T)=\frac{ participants\ who\ is\ at\ least\ 20\ years old}{n}\\\\P(T)=\frac{5}{8}

P(T')=0.63

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