Question

Please Help!
Solve Systems Numerically
f(x)=x^3
g(x)=4x^3-2

Answer 1

What Do You Think

Answer 2

I think it is gof problem but I am not sure.

Answer 3

I will medal and give a testimonial

Answer 4

i have no idea what this means "solve numerically"
do you? are you supposed to solve
\[x^3=4x^3-2\]?

Answer 5

that is not so hard, you get \[3x^3=2\\
x^3=\frac{2}{3}\\
x=\sqrt[3]{\frac{2}{3}}\] but that might not be what the questions is asking

Answer 6

I do not. That is also why I am stuck and confused. She said to start it off like that though so I am going to go with what you replied. Thank you so much for answering.

Answer 7

I need to find y or f(x)) now. Could someone help me do that?

Answer 8

since you know the value of x now just plug it back in to f(x)

Answer 9

that will give you the value of f(x)

Answer 10

Okay, I tried doing that and I got 2/3 so I do not know if I did that right?

Answer 11

yes that is correct

Answer 12

Yes! Thank you. Okay, for the remainder of the question my teacher said to check my answers by making sure if graphed it has to cross the points (2,8). What do you think she means by this..?

Answer 13

cross the point (2,8)?

Answer 14

Yes. She said to check my answers make sure that my graphs cross at (2,8). And if not to double check my algebra.

Answer 15

She sent me this also. It is a very confusing question so I apologize, that is also why I've been stuck on it.

Answer 16

well they dont cross at (2,8) is the problem

Answer 17

you can use this to verify

https://www.desmos.com/calculator

Answer 18

and you can see in the graph she gave you they dont cross at (2,8), so im not sure where that number is coming from

Answer 19

Then I don't know what she wants me to do to solve this problem really. I should be finding a point where (x,y) intersect. And thank you, I will use that. I think she was using a example to show them not crossing.

Answer 20

well they cross when x = $$\sqrt[3]{\frac{2}{3}}$$

so plug that back into f(x) and g(x) and get their values, which will be the same value

you already found that to be 2/3, so they cross at $$(\sqrt[3]{\frac{2}{3}}, 2/3)$$

Answer 21

im not sure where the (2,8) coordinate comes from

Answer 22

So then it's basically at the starting point. I will just go with those because they seem right. Me either. She just said to check your answers by seeing if my functions cross there.

Answer 23

hmm ok, well when you graph it, and find the point(s) they intersect, that is solving for the system graphically

when you do it with algrebra, that is solving for the system "numerically"

Answer 24

if those are for sure the equations you are getting from your teacher, then that is the answer

Answer 25

Yes, the for sure equations are the ones I posted first, the f(x) and g(x) ones.

Answer 26

then yes your answer is the coordinate i posted

Answer 27

Okay, thank you so much. :)

Answer 28

you're welcome