Question

please help :)

Answer 1

@mathmale i already have some info for #3

Answer 2

How would you like for us to start out?

Answer 3

i already have the "a,b,and c " for the quadratic formula

Answer 4

and so your next goal is to do what ?

Answer 5

see this link to see where i am http://openstudy.com/users/plohrr#/updates/52f1599de4b0d693ffe37333

Answer 6

y= 3x + 6 is my linear equation, and we have to build off that for #3

Answer 7

@ranga @timo86m

Answer 8

Your trajectory is y = 3x + 6 ----- (1)
The IH orbit is: y^2 + x^2 = 40,000 ------- (2)
Solve these two equations to find the points where the two paths intersect.

Replace y in (2) with 3x+6 and solve for x and then y.

Answer 9

IDK if they actually want you to solve it or just outline the steps for solving it.

Answer 10

no i think they want to solve it

Answer 11

so sub y into #2?

Answer 12

"Using complete sentences explain HOW to solve" seems to imply they just want you to explain how to solve rather than actually solve.

Answer 13

can we still solve it so i can understand better

Answer 14

sure sub y from (1) into (2) and solve for x first.

Answer 15

\[(3x+6)^2 + x^2 = 40,000\]

Answer 16

Go ahead and solve for x.

Answer 17

how exactly do i do that

Answer 18

do i FOIL out 3x + 6

Answer 19

(a+b)^2 = a^2 + 2ab + b^2

Answer 20

9x^2 + 36x + 36 + x^2

Answer 21

Bring the 40,000 from the right to the left and simplify and then solve the quadratic equation using the quadratic formula.

Answer 22

i don't understand

Answer 23

subtract 40000 from both sides ?

Answer 24

(3x+6)^2 + x^2 = 40,000
9x^2 + 36x + 36 + x^2 = 40,000
10x^2 + 36x + 36 - 40,000 = 0
10x^2 + 36x - 39964 = 0
divide by 10
x^2 + 3.6x - 3996.4 = 0
a = 1, b = 3.6, c = -3996.4
plug it into the quadratic formula and find the two values of x.

Answer 25

x=8?

Answer 26

\[\Large \frac{ -b \pm \sqrt{b ^{2} - 4ac} }{ 2a } = \frac{ -3.6 \pm \sqrt{(3.6) ^{2} - 4(-3996.4)} }{ 2 } \]

Answer 27

\[\frac{ -3.6 \pm \sqrt{(3.6) ^{2} + 15985.6} }{ 2 } = \frac{ -3.6 \pm \sqrt{15998.56} }{ 2 } = \frac{ -3.6 \pm 126.49 }{ 2 } \]

Answer 28

take it from here. Find both x values and then find the corresponding y values. Write the two points as an ordered pair (x,y). Those are the points where the paths will cross.

Answer 29

x = +-130.09

Answer 30

right

Answer 31

\[\frac{ -3.6 \pm 126.49 }{ 2 } = \frac{ -3.6 - 126.49 }{ 2 } or \frac{ -3.6 + 126.49 }{ 2 }\]\[\frac{ -130.09 }{ 2 } ~or~ \frac{122.89 }{ 2 } = -65.0 ~~or~~ 61.4\]

Answer 32

i forgot to divide by 2

Answer 33

ok, now we plug that to find y

Answer 34

Yes.

Answer 35

y^2 + x^2 = 40,000

(3x+6)^2 - 65^2 = 40,000

Answer 36

is this the correct setup

Answer 37

Put it in the other equation which is simpler. The intersection point lies on both equations. So why not choose the simpler equation to solve for y.

y = 3x + 6

Put the two x values and solve for y.

Answer 38

y = 3 (-65) + 6
y = -189

y = 3 (61.4) + 6
y= 190.2

Answer 39

This is correct from where ranga left off

Answer 40

@Loser66

Answer 41

Even though we get two points of intersection after solving the two equations, you can discard the negative solution because the negative point of intersection is on the other side of the earth when the satellite makes a circular orbit around the earth.

Answer 42

so are my x and y values correct

Answer 43

@ganeshie8 @jim_thompson5910 can either of you continue

Answer 44

@satellite73 @Mertsj can you guys help

Answer 45

You can keep (61.4, 190.3) and discard the negative coordinates.

Answer 46

so (61.4, 190.2)