Question

Let f(x)=2x^3-4x+1. Fill in the blank with the number of times the output value (y) occurs for input values of x between -3 and 3 (options listed in answer bank). Graph on your calculator in an appropriate window so you can count how many times.

Answer 1

I am having a little trouble understanding what this question is asking me. Are there any graphing calculators online?

Answer 2

@Michele_Laino

Answer 3

Do they want me to plug those numbers into the formula?

Answer 4

we have to use the graph of your function

Answer 5

I don't know if the link will work but that's the graph I plugged in

Answer 6

here is the procedure wit y=20 and y=-3:

Answer 7

you have to count the intersection points

Answer 8

please I redraw the graph, please wait

Answer 9

for example y=-3 (green horizontal line) give us only one intersection point between the vertical lines at x=-3 and x=3, so we have only one solution

Answer 10

oh so all those numbers are on the y axis 20, -3, 2, -40, and 1

Answer 11

yes!

Answer 12

y=20 (blue horizontal line) gives us only one intersection point between the vertical lines at x=-3 and x=3, so, again, we have only one solution

Answer 13

simlarly with others values y=2, -40, 1

Answer 14

similarly*

Answer 15

what graphing calculator is the one your using?

Answer 16

it is "desmos":
https://www.desmos.com/calculator

Answer 17

ok I going to try the other ones

Answer 18

y=20 (one intersection point)
y=-3 (one intersection point)

This is what I got?
y=2 (three intersection point)
y=-40 (one intersection point)
y=-1(three intersection point)

Answer 19

I did not get 4 anywhere.

Answer 20

ok! correct!

Answer 21

we are not able to get 4 intersection points, because your function is a polynomial of degree= 3, s, at maximum, we get three solutions

Answer 22

so*

Answer 23

ok thank you the desmos calculator is really helpful