How do you graph \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\]?
Answer
630.9k+ views
Hint:We use the definition of hyperbola and write its general equation. Compare the given equation to the general equation of hyperbola and write values of center and vertices.
* General equation of hyperbola having center \[(h,k)\]and vertices \[(h, \pm a)\]is given by the equation \[\dfrac{{{{\left( {x - h} \right)}^2}}}{{{a^2}}} - \dfrac{{{{\left( {y - k} \right)}^2}}}{{{b^2}}} = 1\].
Complete step-by-step answer:
We are given the equation \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\]
We can write this equation in simpler form i.e. \[\dfrac{{{{\left( {x - 0} \right)}^2}}}{{{2^2}}} - \dfrac{{{{\left( {y - 0} \right)}^2}}}{{{3^2}}} = 1\]
On comparing this equation with general equation of hyperbola \[\dfrac{{{{\left( {x - h} \right)}^2}}}{{{a^2}}} - \dfrac{{{{\left( {y - k} \right)}^2}}}{{{b^2}}} = 1\], we get
\[h = 0;k = 0\]
So, the center \[(h,k)\] of the parabola becomes \[(0,0)\] … (1)
Now from comparison we can also write \[a = 2;b = 3\]
So, the vertices \[(h, \pm a)\] of the hyperbola become \[(0, \pm 2)\]
Asymptotes are the straight lines that continuously approach the curve but never meet the curve
Now we can construct the hyperbola \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\] using its center \[(0,0)\] and its vertices \[(0, \pm 2)\]
We know the hyperbola will open in left and right side as the positive value of ‘x’
We first mark the center of hyperbola on the graph and then take 2 units in upward, downward, left and right direction
Now connect these corners as a rectangle and draw lines through corners as asymptotes
Draw hyperbola using the asymptotes opened on right and left side
\[\therefore \]Graph of hyperbola \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\] is
Note:
Many students make mistake of assuming the equation given in the question as equation of an ellipse as they think the general equation of ellipse is \[\dfrac{{{x^2}}}{{{a^2}}} + \dfrac{{{y^2}}}{{{b^2}}} = 1\] and they think negative sign just indicates graph is elliptical in which direction, but this is wrong concept. Keep in mind we never have a negative sign in an ellipse, a negative sign in such an equation tells us that the equation is of hyperbola.
* General equation of hyperbola having center \[(h,k)\]and vertices \[(h, \pm a)\]is given by the equation \[\dfrac{{{{\left( {x - h} \right)}^2}}}{{{a^2}}} - \dfrac{{{{\left( {y - k} \right)}^2}}}{{{b^2}}} = 1\].
Complete step-by-step answer:
We are given the equation \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\]
We can write this equation in simpler form i.e. \[\dfrac{{{{\left( {x - 0} \right)}^2}}}{{{2^2}}} - \dfrac{{{{\left( {y - 0} \right)}^2}}}{{{3^2}}} = 1\]
On comparing this equation with general equation of hyperbola \[\dfrac{{{{\left( {x - h} \right)}^2}}}{{{a^2}}} - \dfrac{{{{\left( {y - k} \right)}^2}}}{{{b^2}}} = 1\], we get
\[h = 0;k = 0\]
So, the center \[(h,k)\] of the parabola becomes \[(0,0)\] … (1)
Now from comparison we can also write \[a = 2;b = 3\]
So, the vertices \[(h, \pm a)\] of the hyperbola become \[(0, \pm 2)\]
Asymptotes are the straight lines that continuously approach the curve but never meet the curve
Now we can construct the hyperbola \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\] using its center \[(0,0)\] and its vertices \[(0, \pm 2)\]
We know the hyperbola will open in left and right side as the positive value of ‘x’
We first mark the center of hyperbola on the graph and then take 2 units in upward, downward, left and right direction
Now connect these corners as a rectangle and draw lines through corners as asymptotes
Draw hyperbola using the asymptotes opened on right and left side
\[\therefore \]Graph of hyperbola \[\left( {\dfrac{{{x^2}}}{4}} \right) - \left( {\dfrac{{{y^2}}}{9}} \right) = 1\] is
Note:
Many students make mistake of assuming the equation given in the question as equation of an ellipse as they think the general equation of ellipse is \[\dfrac{{{x^2}}}{{{a^2}}} + \dfrac{{{y^2}}}{{{b^2}}} = 1\] and they think negative sign just indicates graph is elliptical in which direction, but this is wrong concept. Keep in mind we never have a negative sign in an ellipse, a negative sign in such an equation tells us that the equation is of hyperbola.
Recently Updated Pages
What is BLO What is the full form of BLO class 8 social science CBSE

Explain the Treaty of Vienna of 1815 class 10 social science CBSE

10 examples of friction in our daily life

Draw a diagram of nephron and explain its structur class 11 biology CBSE

Write structures of the following compounds i 2 Chloro3methylpentane class 11 chemistry CBSE

A Paragraph on Pollution in about 100-150 Words

Trending doubts
Draw a labelled sketch of the human eye class 12 physics CBSE

Which are the Top 10 Largest Countries of the World?

Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE

Draw ray diagrams each showing i myopic eye and ii class 12 physics CBSE

Which is the correct genotypic ratio of mendel dihybrid class 12 biology CBSE

What is the Full Form of PVC, PET, HDPE, LDPE, PP and PS ?

