Can someone correct my questions and help me please.

  • Thread starter Thread starter 54088
  • Start date Start date
Click For Summary

Homework Help Overview

The discussion revolves around finding points of intersection between a line and a curve defined by the equations y = x + 2 and 4y + 3x^2 = 7. The original poster presents a multi-part question involving both finding coordinates of intersections and determining a function with a specified gradient.

Discussion Character

  • Mixed

Approaches and Questions Raised

  • Participants explore substitution methods to find intersection points and discuss the implications of a line having a specific gradient. There are attempts to derive the function f(x) based on the given gradient and to analyze the conditions for a single point of intersection.

Discussion Status

Some participants have provided insights into the problem, particularly regarding the gradient and the resulting equations. There is acknowledgment of the need for further exploration of the original poster's questions, but no explicit consensus has been reached on the solutions.

Contextual Notes

Participants emphasize that the original poster should engage with the problem independently and not rely on others to complete their homework tasks.

54088
Messages
13
Reaction score
0
The line y = x + 2 intersects the curve 4y + 3x^2 = 7 in two places.

a) Find the coordinates of the two points of intersections.

>Sub. y = x + 2 to 4y + 3x^2 = 7
>4(x+2) + 3x^2 = 7
>4x + 8 + 3x^2 -7 = 0
>3x^2 + 4x -1 = 0
>x = -1 and - 1/3
>y = x + 2
>so y = 1 or 5/3

The straight line y = f(x) has gradient 3 and intersects the curve 4y + 3x^2 = 7 at one point only.

b) Find f(x).

>?

c) Hence find the coordinates of the point of intersection between y = f(x) and 4y + 3x^2 =7

>?

:(
 
Physics news on Phys.org
to question b)
we know that y = f(x) has gradient 3, so y=3x+m, and 4y+3x^2=7
>4(3x+m)+3x^2=7
>3x^2+12x+4m-7=0
at one point only, so the equation above has only one solution, Δ=0
>m=17/4

q c) is easy ^.^
 
Thankyou Very Much! ^^"
 
54088 said:
The line y = x + 2 intersects the curve 4y + 3x^2 = 7 in two places.

a) Find the coordinates of the two points of intersections.

>Sub. y = x + 2 to 4y + 3x^2 = 7
>4(x+2) + 3x^2 = 7
>4x + 8 + 3x^2 -7 = 0
>3x^2 + 4x -1 = 0
>x = -1 and - 1/3
>y = x + 2
>so y = 1 or 5/3

The straight line y = f(x) has gradient 3 and intersects the curve 4y + 3x^2 = 7 at one point only.

b) Find f(x).

>?

c) Hence find the coordinates of the point of intersection between y = f(x) and 4y + 3x^2 =7

>?

:(

i think that alright you aint to old or to young to learn more
 
mensa said:
to question b)
we know that y = f(x) has gradient 3, so y=3x+m, and 4y+3x^2=7
>4(3x+m)+3x^2=7
>3x^2+12x+4m-7=0
at one point only, so the equation above has only one solution, Δ=0
>m=17/4

q c) is easy ^.^

Do NOT do the OP's work for them. They are required to do their own homework here at the PF.
 

Similar threads

Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
1
Views
2K
Replies
4
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
  • · Replies 14 ·
Replies
14
Views
4K
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
8
Views
3K