Indentify the typer of conic section and its vertices&foci. Calc II

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SUMMARY

The conic section represented by the equation y² + 2y = 4x² + 3 is identified as a hyperbola. This conclusion is drawn from the opposite signs of the squared terms in the equation. The completed square form reveals the center at (0, -1), with vertices located at (0, 1) and (0, -3). The foci are calculated to be at (0, -1 ± √5), derived from the relationship c² = a² + b², where a² = 4 and b² = 1.

PREREQUISITES
  • Understanding of conic sections, specifically hyperbolas
  • Ability to complete the square in quadratic equations
  • Familiarity with the standard form of hyperbola equations
  • Knowledge of calculating vertices and foci from hyperbola equations
NEXT STEPS
  • Study the properties of hyperbolas, including asymptotes and directrices
  • Learn how to derive the equations of ellipses and parabolas for comparison
  • Practice completing the square for various quadratic equations
  • Explore applications of conic sections in real-world scenarios, such as satellite orbits
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Students studying calculus, particularly those focusing on conic sections, as well as educators teaching these concepts in mathematics courses.

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Homework Statement



Identify the type of conic section whose equation is given as y^2+2y=4x^2+3
Also find its vertices and foci
(y-k)^2/a^2-(x-h)^2/b^2=1

Homework Equations



I believe when you have x&y ^2 in an equation it can be either an ellipse or a hyperbola but if the signs are opposite it is a hyperbola. vertices ± a from center, foci ± c from center.

The Attempt at a Solution


I begin by rewriting the equation y^2+2y=4x^2+3 as
y^2+2y-4x^2=3 thus allowing me to recognize that the powers or x/y ^2 are opposite, and thus the type of conic section is a hyperbola.
I complete the square for the y(s) of the equation which gives me (y+1)^2-1
and I now rewrite the equation as (y+1)^2-4x^2=3+1, (y+1)^2-4x^2=4
there is no way of completing the square for 4x^2 however since I know the equation is in the form (x-h)^2 I will rewrite -4x^2 as -4(x-0)^2
I will rewrite the equation again as:
(y+1)^2-4(x-0)^2=4 and again in the form of (y-k)^2/a^2-(x-h)^2/b^2=1
as, (y+1)^2/4 - (x-0)^2/1 = 1
thus I have a^2=4, b^2=1, and a=2, b=1
I know have all the necessary things to solve for the question.
Center = (h,k)= (0,-1)
vertices are ± a from center on axis, a =2
thus vertices are (0,-1 ± 2 )
foci are ± c from center, c^2=a^2+b^2= 1+4= √5
foci: (0, -1±√5)

That is all my work/solutions for this problem.
Any help with what I may have done wrong and how to learn how to correct is, or even just saying "correct" is appreciated thank you.
 
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StudentofSci said:

Homework Statement



Identify the type of conic section whose equation is given as y^2+2y=4x^2+3
Also find its vertices and foci
(y-k)^2/a^2-(x-h)^2/b^2=1

Homework Equations



I believe when you have x&y ^2 in an equation it can be either an ellipse or a hyperbola but if the signs are opposite it is a hyperbola. vertices ± a from center, foci ± c from center.

The Attempt at a Solution


I begin by rewriting the equation y^2+2y=4x^2+3 as
y^2+2y-4x^2=3 thus allowing me to recognize that the powers or x/y ^2 are opposite, and thus the type of conic section is a hyperbola.
I complete the square for the y(s) of the equation which gives me (y+1)^2-1
and I now rewrite the equation as (y+1)^2-4x^2=3+1, (y+1)^2-4x^2=4
there is no way of completing the square for 4x^2 however since I know the equation is in the form (x-h)^2 I will rewrite -4x^2 as -4(x-0)^2
Yes, that is "completing the square" for x^2.

I will rewrite the equation again as:
(y+1)^2-4(x-0)^2=4 and again in the form of (y-k)^2/a^2-(x-h)^2/b^2=1
as, (y+1)^2/4 - (x-0)^2/1 = 1
thus I have a^2=4, b^2=1, and a=2, b=1
I know have all the necessary things to solve for the question.
Center = (h,k)= (0,-1)
vertices are ± a from center on axis, a =2
thus vertices are (0,-1 ± 2 )
foci are ± c from center, c^2=a^2+b^2= 1+4= √5
foci: (0, -1±√5)

That is all my work/solutions for this problem.
Any help with what I may have done wrong and how to learn how to correct is, or even just saying "correct" is appreciated thank you.
It all looks correct to me.
 

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