Can someone correct my questions and help me please.

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The discussion revolves around finding the points of intersection between the line y = x + 2 and the curve 4y + 3x^2 = 7, which intersect at two points: (-1, 1) and (-1/3, 5/3). For the second part, the line y = f(x) with a gradient of 3 intersects the curve at one point, leading to the equation 4(3x + m) + 3x^2 = 7. The condition for a single intersection point requires the discriminant to equal zero, resulting in m = 17/4. The final coordinates of the intersection point can be derived easily from this information.
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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

>?

:(
 
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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.
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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