Question

for what values of m does the line with equation y = mx - 12 not intersect or touch the parabola with equation y = 2x^2-x-10. Please show working out & explain.

Answer 1

This has got me stumped and I need to know too, lol!

Answer 2

I'm gonna post this on another forum and see if I get a response.

Answer 3

if you're in Calculus ... could be done easily ... not sure what math are you taking...

Answer 4

I'm a total dork. I took precalc 5 years ago. So I'm embarrassed

Answer 5

math, if you remember then can you post the solution or at least part of it?

Answer 6

LOL... this is quadratics functions just to let u know. Hopefully u will be able to answer my question soon enough. I am also taking Maths Methods and do not know what is calculus lol.

Answer 7

Well they talk about this stuff in precalc.

Answer 8

So mathg8 is telling me that "I should know this" but it looks like he's not posting ANYthing.

Answer 9

thinking how would i do it with algebra ...

Answer 10

sorry I'm not very familiar with calculus & precalc stuff. I just know this was one of my questions I had to do on my practice test or SAC if u know what it is and ur weren't allowed to use a calculator for it, so I want the working out/solutions as to how it can be solved.

Answer 11

0 would work for sure

Answer 12

below the vertex

Answer 13

well yeah

Answer 14

I'm interested in the algebraic method of solving this. I feel completely lost on it and it's bugging me.

Answer 15

do you need one value or a range of values?

Answer 16

I'll bring the problem in to my old calc teacher and she'll probably beat me with an eraser!

Answer 17

LOL. Well I do have the answer that I copied from the board which the teacher wrote. The teacher only wrote the answer. I can tell u the answer but I wanted to know if u could show me the working out and confirm the answer for me instead of providing u with the answer straight away. The answer is a range of values btw.

Answer 18

so it is calculus

Answer 19

take the derivative

Answer 20

I took calc 1-3 about 5 years ago. And I got into math again just recently.

Answer 21

yes Quadratic Functions, but try solving it without calculator (as I was not allowed one) and show me all the working out with it.

Answer 22

y= 4x-1 ( the slope of all tangent lines to the parabola )

Answer 23

the line parallel to one of the tangents has the same slope

Answer 24

Jay, what answer did you get?

Answer 25

m=4x-1 as you plug in values for x you'll find the values ... I'm not seeing any restrictions for x

Answer 26

It's not my answer, it's the teacher's answer just to let u know. It's -3<m<5. Please help me obtain the solutions/working out, I urgently need to understand this.

Answer 27

so there are some restrictions ... I was wondering and just tried -1 ...doesn't work

Answer 28

So I guess you could set mx-12 = 2x^2 -x-10 and solve for m. Those will be the slopes which the line intersects I believe? So then you pick the range where it does not intersect.

Answer 29

-1 is between -3 and 5 and it doesn't work ...

Answer 30

I'm not too sure but this is the answer that I copied from the board.

Answer 31

-5<m<3

Answer 32

did you get 3 and -5 switched ?

Answer 33

I'm not sure that I copied it wrong or if the teacher has the wrong answer. I do not even know how to get to the answer.

Answer 34

2x^2 -x -10 =mx-12
find the determinant and make it < 0 ( 2 imaginary solutions)
2x^2-x-mx-10+12 = 0
D = (1+m)^2 -16 < 0
(1+m)^2 < 16
1+m < 4, m< 3
1+m < -4 , m<-5

-5<m<3