Question

f(x)=610x^2-10,250x+1,235 determine the max or min and write answer as a coordinate????

Answer 1

I see it has a minimum. Do you see that?

Answer 2

yes because it's postive right

Answer 3

Yes.

Answer 4

And that minimum is the vertex. Right?

Answer 5

right

Answer 6

And the x coordinate of the vertex can easily be found because we know that x = -b/2a
Right?

Answer 7

right

Answer 8

oh by the way it says x=.28 and then it says to determine the min and write as coordinate, idk if .28 makes any difference

Answer 9

And -b/2a= 10250/1220=8.40

Answer 10

Maybe you'd better post the entire problem.

Answer 11

ok hold on

Answer 12

evaluate each expression below for x=.28. determine the max or min of f(X)=610x^2-10250x+1235. write answer as a coordinate.

Answer 13

Ok. We can do that at the end. Right now we're in the middle of finding the vertex. So do you agree that the x coordinate of the vertex is 8.40?

Answer 14

yes i agree

Answer 15

So now we can find the y coordinate of the vertex by replacing x with 8.40 and evaluating the expression.

Answer 16

I got -41823.4 What did you get?

Answer 17

-4.18234

Answer 18

How did you get a decimal point after the 4?

Answer 19

let me calculate it again ok

Answer 20

The numbers are right. just the decimal is off.

Answer 21

maybe your calculator is in scientific notation mode and it has an exponent of 4. Could that be?

Answer 22

is cuz i set it to round and it's literallly going crazy so let's go with ur answer ok

Answer 23

Ok. Now we know the vertex is (8.4,-41823.4)

Answer 24

And now we have to plug in the .28 and find the value of the expression for that x value.

Answer 25

ok

Answer 26

I got -6917.176 What did you get?

Answer 27

-6.917176

Answer 28

the decimal again

Answer 29

you've got to get your calculator out of scientific notation mode. Do you have a EE button?

Answer 30

It automatically gives you your answers in scientific notation and you are overlooking the number at the upper right of the screen that tells you the exponent of the 10

Answer 31

i redid it and now i got -1.59??????

Answer 32

I'll do it again. I'll bet that every problem you do, you get an answer between 1 and 10. Am I right? Enter 20 times 500

Answer 33

1.00

Answer 34

There you go. Of course 20 times 500 is 10000 not 1. Did you look for a little number at the upper right of your screen? It should be a 4

Answer 35

In any case, I've double checked it a number of times.
f(.28)=-1587.176

Answer 36

so ok then how do i write it as a coordinate?

Answer 37

(.28,-1587.176)

Answer 38

And for the vertex: Ok. Now we know the vertex is (8.4,-41823.4)

Answer 39

yes ok i'm clear now

Answer 40

Good for you.

Answer 41

thank you!!!!!!!!

Answer 42

yw