Pls help me.........

A bridge in the shape of an arch connects two cities separated by a river. The two ends of the bridge are located at (–7, –13) a

sdas [7]

Answer:

$y=-\dfrac{13}{49}x^2$

Step-by-step explanation:

The shape of an arch corresponds to a parabola.

the general equation for a parabola is:

$y=ax^2+bx+c$

we're given three coordinates: (-7,-13),(7,-13) and (0,0)

so we can plug these values in the general equation to make 3 separate equations:

(x,y) = (-7,-13)

$-13=a(-7)^2+b(-7)+c$

$49a-7b+c=-13$

(x,y) = (7,-13)

$-13=a(7)^2+b(7)+c$

$49a+7b+c=-13$

(x,y) = (0,0)

$0=a(0)^2+b(7)+c$

$c=0$

so we have three equations. and we can solve them simultaneously to find the values of a,b, and c.

we've already found c = 0, let's use substitute it to other equations.

$49a-7b+c=-13\quad\Rightarrow\quad49a-7b=-13$

$49a+7b+c=-13\quad\Rightarrow\quad49a+7b=-13$

we can solve these two equation using the elimination method, by simply adding the two equations

$\quad\quad49a-7b=-13\\+\quad49a+7b=-13$

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

$\quad\quad 98a=-26$

$\quad\quad a=-\dfrac{13}{49}$

Now we can plug this value of a in any of the two equations.

$49a-7b=-13$

$49\left(-\dfrac{13}{49}\right)-7b=-13$

$-13-7b=-13$

$-7b=0$

$b=0$

We have the values of a,b, and c. We can plug them in the general equation to find the equation of the arch.

$y=\left(-\dfrac{13}{49}\right)x^2+0x+0$

$y=-\dfrac{13}{49}x^2$

$49y=-13x^2$

This our equation of the arch!

5 0

2 years ago

Triangle EFG is dilated by a scale factor of 3 centered at (0, 1) to create triangle E'F'G'. Which statement is true about the d

jolli1 [7]

Answer:

Segment EH and segment E prime H prime both pass through the center of dilation (A)

The complete question related to this found on brainly (ID:16812154) is stated below:

Triangle EFG is dilated by a scale factor of 3 centered at (0, 1) to create triangle E'F'G'. Which statement is true about the dilation?

E(0,5) F(1,1) G(-2,1) H(0,1)

a) segment EH and segment E prime H prime both pass through the center of dilation.

b)The slope of segment EF is the same as the slope of segment E prime H prime.

c) segment E prime G prime will overlap segment EG. segment

d) EH ≅ segment E prime H prime.

Step-by-step explanation:

∆EFG = Original image

∆EFG is dilated to give ∆E'F'G'

∆E'F'G' = New image

Scale factor = 3

Center of dilation = (0,1) = H(0,1)

Coordinates ∆EFG : E(0,5) F(1,1) G(-2,1)

To determine the statement that is true about the dilation from the options,

First we would make a diagram on the coordinates of ∆EFG and center of dilation (H).

Find attached the diagram.

Length GF = 3unit

Length G'F' = 3×scale factor = 9unit

Length EH = 4unit

Length E'H' = 4×scale factor = 12unit

Then we would move 3units to the left on same line from G to get the coordinate of G'(mark the point).

Also move 3units to the right on same line from F to get the coordinate of F'(mark the point).

Both of these give length of G'F' = 9unit

Now move 8units to the top from E to get the coordinate of E'(mark the point).

From this you get length E'H' = 12unit

Draw lines connecting the three points to get ∆E'F'G'

See diagram for better understanding

From the diagram, EH and E'H' both pass through (0,1). The other options are wrong.

Therefore, Segment EH and segment E prime H prime both pass through the center of dilation (A)

5 0

3 years ago

0.0176165803 is estimated to what

bezimeni [28]

It most common to round to the hundredths place, this is two spaces after the decimal.

So look two spaces right - 0.17. If the third digit (in this case 6) is higher than 5 you round the number up if its not, keep it the same.

"6" is greater than five, so round it to about (or approximately) 0.18.

5 0

3 years ago

1/2a + (-3a) - 3b - 0.7a

Anna71 [15]

If you would like to calculate 1/2 * a + (-3 * a) - 3 * b - 0.7 * a, you can do this using the following steps:

1/2 * a + (-3 * a) - 3 * b - 0.7 * a = 0.5 * a - 3 * a - 0.7 * a - 3 * b = - 3.2 * a - 3 * b

The correct result would be - 3.2 * a - 3 * b.

5 0

2 years ago

7,018 mm = 7.018 A. km B. m C. dm D. cm

Ymorist [56]

Answer: B

Step-by-step explanation:

4 0

3 years ago