Mathematics Dictionary
Dr. K. G. Shih
Parametric Equation
Subjects
Read Symbol defintion
Q01 |
- Parametric equation : x = tan(t) and y = sec(t)
Q02 |
- Parametric equation : x = sec(t) and y = tan(t)
Q03 |
- Diagrams of unit circle and unit hyperbola
Answers
Q01. Parametric equation : x = tan(t) and y = sec(t)
Question 1 : Find coordiantes of the foci
Change to standard form of hyperbola
Since 1 + tan(t)^2 = sec(t)^2
If x = tan(t) and y = sec(t)
Then 1 + x^2 = y^2
Hence x^2 - y^2 = -1
This is a hyperbola with principal axis y = 0
Focal length f = Sqr(a^2 + b^2)
Center is at (0,0)
Vertices are at (0, 1) and (0, -1)
Foci are at (0, Sqr(2)) and (0, -Sqr(2))
Question 2 : Find the asymptotes
y = +x is the asymptote
y = -x is the asymptote
Note : Standard form of hyperbola
(x/a)^2 - (y/b)^2 = +1 with principal axis x = 0
(x/a)^2 - (y/b)^2 = -1 with principal axis y = 0
Focal length f = Sqr(a^2 + b^2)
Reference
1.
keyword Unit Hyperbola
2.
Analytic geometric Section 08
Go to Begin
Q02. Parametric equation : x = sec(t) and y = tan(t)
Question 1 : Find coordiantes of the foci
Change to standard form of hyperbola
Since 1 + tan(t)^2 = sec(t)^2
If x = sec(t) and y = tan(t)
Then 1 + y^2 = x^2
Hence x^2 - y^2 = +1
This is a hyperbola with principal axis x = 0
Focal length f = Sqr(a^2 + b^2)
Center is at (0,0)
Vertices are at (1, 0) and (-1, 0)
Foci are at (Sqr(2), 0) and (-Sqr(2), 0)
Question 2 : Find the asymptotes
y = +x is the asymptote
y = -x is the asymptote
Note : Standard form of hyperbola
(x/a)^2 - (y/b)^2 = +1 with principal axis x = 0
(x/a)^2 - (y/b)^2 = -1 with principal axis y = 0
Focal length f = Sqr(a^2 + b^2)
Reference
1.
keyword Unit Hyperbola
2.
Analytic geometric Section 08
Go to Begin
Q03 Diagrams of unit circle and hyperbola
Find the parametric equations of unit hyperbola
1. Find the curve of x = tan(t) and y = sec(t)
2. Find the curve of x = cot(t) and y = csc(t)
3. Find the curve of x = sec(t) and y = tan(t)
4. Find the curve of x = csc(t) and y = cot(t)
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