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 Page 1


Solved Examples on Parabola 
Q1: The equation of parabola whose focus is (?? , ?? ) and directrix is ?? ?? -
?? ?? + ?? = ?? , is 
(a) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(b) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(c) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(d) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
Ans: (a)  
Sol: 
 
?? ?? 2
= ?? ?? 2
? (?? - 5)
2
+ (?? - 3)
2
= (
3?? - 4?? + 1
v9 + 16
)
2
 ? 25(?? 2
+ 25 - 10?? + ?? 2
+ 9 - 6?? )
 = 9?? 2
+ 16?? 2
+ 1 - 12???? + 6?? - 8?? - 12????
 ? 16?? 2
+ 9?? 2
- 256?? - 142 ?? + 24???? + 849 = 0
 ? (4?? + 3?? )
2
- 256?? - 142 ?? + 849 = 0
 
Q2: The point on the parabola ?? ?? = ?? ?? . Whose distance from the focus is 8 , 
has ?? -coordinate as 
(a) 0 
(b) 2 
(c) 4 
(d) 6 
Ans: (d)  
Sol: If ?? (?? 1
, ?? 1
) is a point on the parabola ?? 2
= 4???? and S is its focus, then ???? =
Page 2


Solved Examples on Parabola 
Q1: The equation of parabola whose focus is (?? , ?? ) and directrix is ?? ?? -
?? ?? + ?? = ?? , is 
(a) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(b) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(c) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(d) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
Ans: (a)  
Sol: 
 
?? ?? 2
= ?? ?? 2
? (?? - 5)
2
+ (?? - 3)
2
= (
3?? - 4?? + 1
v9 + 16
)
2
 ? 25(?? 2
+ 25 - 10?? + ?? 2
+ 9 - 6?? )
 = 9?? 2
+ 16?? 2
+ 1 - 12???? + 6?? - 8?? - 12????
 ? 16?? 2
+ 9?? 2
- 256?? - 142 ?? + 24???? + 849 = 0
 ? (4?? + 3?? )
2
- 256?? - 142 ?? + 849 = 0
 
Q2: The point on the parabola ?? ?? = ?? ?? . Whose distance from the focus is 8 , 
has ?? -coordinate as 
(a) 0 
(b) 2 
(c) 4 
(d) 6 
Ans: (d)  
Sol: If ?? (?? 1
, ?? 1
) is a point on the parabola ?? 2
= 4???? and S is its focus, then ???? =
?? 1
+ ?? 
Here 4?? = 8 ? ?? = 2; ???? = 8 
? 8 = ?? 1
+ 2 ? ?? 1
= 6 
Q3: If the parabola ?? ?? = ?? ax passes through (-?? , ?? ), then length of its latus 
rectum is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) 4 
Ans: (c) 
Sol: The point (-3,2) will satisfy the equation ?? 2
= 4???? ? 4 = -12?? ? Latus 
rectum = 4|?? | = 4 × |-
1
3
| =
4
3
 
Q4: The equation of the parabola with its vertex at the origin, axis on the ?? -
axis and passing through the point (?? , -?? ) is 
(a) ?? ?? = ???? ?? + ?? 
(b) ?? ?? = ???? ?? 
(c) ?? ?? = -???? ?? 
(d) ?? ?? = -???? ?? + ?? 
Ans: (c) 
Sol: Since the axis of parabola is ?? -axis with its vertex at origin. 
? Equation of parabola ?? 2
= 4???? . Since it passes through (6, -3) ; 
? 36 = -12?? ? ?? = -3 
? Equation of parabola is ?? 2
= -12?? . 
Q5: The line ?? - ?? = ?? is the directrix of the parabola ?? ?? - ???? + ?? = ?? . Then 
one of the values of ?? is 
(a) 
?? ?? 
(b) 8 
(c) 4 
Page 3


Solved Examples on Parabola 
Q1: The equation of parabola whose focus is (?? , ?? ) and directrix is ?? ?? -
?? ?? + ?? = ?? , is 
(a) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(b) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(c) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(d) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
Ans: (a)  
Sol: 
 
?? ?? 2
= ?? ?? 2
? (?? - 5)
2
+ (?? - 3)
2
= (
3?? - 4?? + 1
v9 + 16
)
2
 ? 25(?? 2
+ 25 - 10?? + ?? 2
+ 9 - 6?? )
 = 9?? 2
+ 16?? 2
+ 1 - 12???? + 6?? - 8?? - 12????
 ? 16?? 2
+ 9?? 2
- 256?? - 142 ?? + 24???? + 849 = 0
 ? (4?? + 3?? )
2
- 256?? - 142 ?? + 849 = 0
 
Q2: The point on the parabola ?? ?? = ?? ?? . Whose distance from the focus is 8 , 
has ?? -coordinate as 
(a) 0 
(b) 2 
(c) 4 
(d) 6 
Ans: (d)  
Sol: If ?? (?? 1
, ?? 1
) is a point on the parabola ?? 2
= 4???? and S is its focus, then ???? =
?? 1
+ ?? 
Here 4?? = 8 ? ?? = 2; ???? = 8 
? 8 = ?? 1
+ 2 ? ?? 1
= 6 
Q3: If the parabola ?? ?? = ?? ax passes through (-?? , ?? ), then length of its latus 
rectum is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) 4 
Ans: (c) 
Sol: The point (-3,2) will satisfy the equation ?? 2
= 4???? ? 4 = -12?? ? Latus 
rectum = 4|?? | = 4 × |-
1
3
| =
4
3
 
Q4: The equation of the parabola with its vertex at the origin, axis on the ?? -
axis and passing through the point (?? , -?? ) is 
(a) ?? ?? = ???? ?? + ?? 
(b) ?? ?? = ???? ?? 
(c) ?? ?? = -???? ?? 
(d) ?? ?? = -???? ?? + ?? 
Ans: (c) 
Sol: Since the axis of parabola is ?? -axis with its vertex at origin. 
? Equation of parabola ?? 2
= 4???? . Since it passes through (6, -3) ; 
? 36 = -12?? ? ?? = -3 
? Equation of parabola is ?? 2
= -12?? . 
Q5: The line ?? - ?? = ?? is the directrix of the parabola ?? ?? - ???? + ?? = ?? . Then 
one of the values of ?? is 
(a) 
?? ?? 
(b) 8 
(c) 4 
(d) 
?? ?? 
Ans: (c)  
Sol: The parabola is ?? 2
= 4
?? 4
(?? -
8
?? ). Putting ?? = ?? , ?? -
8
?? = ?? . The equation is 
?? 2
= 4 ·
?? 4
· ?? 
? The directrix is ?? +
?? 4
= 0 i.e., ?? -
8
?? +
?? 4
= 0. But ?? - 1 = 0 is the directrix. So 
8
?? -
?? 4
= 1 ? ?? = -8,4 
Q6: The ends of a line segment are ?? (?? , ?? ) and ?? (?? , ?? ). ?? is a point on the 
line segment ???? such that ???? : ???? = ?? : ?? . If ?? is an interior point of the 
parabola ?? ?? = ?? ?? , then 
(a) ?? ? (?? , ?? ) 
(b) ?? ? (-
?? ?? , ?? ) 
(c) ?? ? (
?? ?? ,
?? ?? ) 
(d) None of these 
Ans: (a)  
Sol:  ?? = (1,
1+3?? 1+?? ) It is an interior point of ?? 2
- 4?? = 0 iff (
1+3?? 1+?? )
2
- 4 < 0 
? (
1 + 3?? 1 + ?? - 2) (
1 + 3?? 1 + ?? + 2) < 0 ? (
?? - 1
1 + ?? ) (
5?? + 3
1 + ?? ) < 0 ? (?? - 1)(?? +
3
5
) < 0 
Therefore, -
3
5
< ?? < 1. But ?? > 0 ? 0 < ?? < 1 ? ?? ? (0,1). 
Q7: The equation of the tangent to the parabola ?? ?? = ???? ?? , which is 
perpendicular to the line ?? = ?? ?? + ?? is 
(a) ?? - ?? ?? + ?? = ?? 
(b) ?? ?? - ?? + ???? = ?? 
(c) ?? ?? + ?? - ???? = ?? 
(d) ?? ?? + ?? + ???? = ?? 
Ans: (a)  
Page 4


Solved Examples on Parabola 
Q1: The equation of parabola whose focus is (?? , ?? ) and directrix is ?? ?? -
?? ?? + ?? = ?? , is 
(a) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(b) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(c) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(d) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
Ans: (a)  
Sol: 
 
?? ?? 2
= ?? ?? 2
? (?? - 5)
2
+ (?? - 3)
2
= (
3?? - 4?? + 1
v9 + 16
)
2
 ? 25(?? 2
+ 25 - 10?? + ?? 2
+ 9 - 6?? )
 = 9?? 2
+ 16?? 2
+ 1 - 12???? + 6?? - 8?? - 12????
 ? 16?? 2
+ 9?? 2
- 256?? - 142 ?? + 24???? + 849 = 0
 ? (4?? + 3?? )
2
- 256?? - 142 ?? + 849 = 0
 
Q2: The point on the parabola ?? ?? = ?? ?? . Whose distance from the focus is 8 , 
has ?? -coordinate as 
(a) 0 
(b) 2 
(c) 4 
(d) 6 
Ans: (d)  
Sol: If ?? (?? 1
, ?? 1
) is a point on the parabola ?? 2
= 4???? and S is its focus, then ???? =
?? 1
+ ?? 
Here 4?? = 8 ? ?? = 2; ???? = 8 
? 8 = ?? 1
+ 2 ? ?? 1
= 6 
Q3: If the parabola ?? ?? = ?? ax passes through (-?? , ?? ), then length of its latus 
rectum is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) 4 
Ans: (c) 
Sol: The point (-3,2) will satisfy the equation ?? 2
= 4???? ? 4 = -12?? ? Latus 
rectum = 4|?? | = 4 × |-
1
3
| =
4
3
 
Q4: The equation of the parabola with its vertex at the origin, axis on the ?? -
axis and passing through the point (?? , -?? ) is 
(a) ?? ?? = ???? ?? + ?? 
(b) ?? ?? = ???? ?? 
(c) ?? ?? = -???? ?? 
(d) ?? ?? = -???? ?? + ?? 
Ans: (c) 
Sol: Since the axis of parabola is ?? -axis with its vertex at origin. 
? Equation of parabola ?? 2
= 4???? . Since it passes through (6, -3) ; 
? 36 = -12?? ? ?? = -3 
? Equation of parabola is ?? 2
= -12?? . 
Q5: The line ?? - ?? = ?? is the directrix of the parabola ?? ?? - ???? + ?? = ?? . Then 
one of the values of ?? is 
(a) 
?? ?? 
(b) 8 
(c) 4 
(d) 
?? ?? 
Ans: (c)  
Sol: The parabola is ?? 2
= 4
?? 4
(?? -
8
?? ). Putting ?? = ?? , ?? -
8
?? = ?? . The equation is 
?? 2
= 4 ·
?? 4
· ?? 
? The directrix is ?? +
?? 4
= 0 i.e., ?? -
8
?? +
?? 4
= 0. But ?? - 1 = 0 is the directrix. So 
8
?? -
?? 4
= 1 ? ?? = -8,4 
Q6: The ends of a line segment are ?? (?? , ?? ) and ?? (?? , ?? ). ?? is a point on the 
line segment ???? such that ???? : ???? = ?? : ?? . If ?? is an interior point of the 
parabola ?? ?? = ?? ?? , then 
(a) ?? ? (?? , ?? ) 
(b) ?? ? (-
?? ?? , ?? ) 
(c) ?? ? (
?? ?? ,
?? ?? ) 
(d) None of these 
Ans: (a)  
Sol:  ?? = (1,
1+3?? 1+?? ) It is an interior point of ?? 2
- 4?? = 0 iff (
1+3?? 1+?? )
2
- 4 < 0 
? (
1 + 3?? 1 + ?? - 2) (
1 + 3?? 1 + ?? + 2) < 0 ? (
?? - 1
1 + ?? ) (
5?? + 3
1 + ?? ) < 0 ? (?? - 1)(?? +
3
5
) < 0 
Therefore, -
3
5
< ?? < 1. But ?? > 0 ? 0 < ?? < 1 ? ?? ? (0,1). 
Q7: The equation of the tangent to the parabola ?? ?? = ???? ?? , which is 
perpendicular to the line ?? = ?? ?? + ?? is 
(a) ?? - ?? ?? + ?? = ?? 
(b) ?? ?? - ?? + ???? = ?? 
(c) ?? ?? + ?? - ???? = ?? 
(d) ?? ?? + ?? + ???? = ?? 
Ans: (a)  
Sol: A line perpendicular to the given line is 3?? + ?? = ?? ? ?? = -
1
3
?? +
?? 3
 
Here ?? = -
1
3
, ?? =
?? 3
. If we compare ?? 2
= 16?? with ?? 2
= 4???? , then ?? = 4 
Condition for tangency is ?? =
?? ?? ?
?? 3
=
4
(-1/3)
? ?? = -36 … Required equation is 
?? + 3?? + 36 = 0. 
Q8: Two tangents are drawn from the point (-?? , -?? ) to the parabola ?? ?? =
?? ?? . If ?? is the angle between these tangents, then tan ?? = 
(a) 3 
(b) ?? /?? 
(c) 2 
(d) ½ 
Ans: (a) 
Sol: Equation of pair of tangent from (-2, -1) to the parabola is given by SS
1
=
?? 2
 i.e. (?? 2
- 4?? )(1 + 8) = [?? (-1) - 2(?? - 2)]
2
 
 ? 9?? 2
- 36?? = [-?? - 2?? + 4]
2
? 9?? 2
- 36?? = ?? 2
+ 4?? 2
+ 16 + 4???? - 16?? - 8?? ? 4?? 2
- 8?? 2
+ 4???? + 20?? - 8?? + 16 = 0
 ? tan ?? = |
2vh
2
- ????
?? + ?? | = |
2v4 - 4(-8)
4 - 8
| = |
12
-4
| = 3
 
Q9: If (
?? ?? )
?? /?? + (
?? ?? )
?? /?? =
v?? ?? , then the angle of intersection of the parabola ?? ?? =
?? ???? and ?? ?? = ?? ???? at a point other than the origin is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) None of these 
Ans: (b) 
Sol: 
Given parabolas are ?? 2
= 4????   … ..(i) and ?? 2
= 4????    …… (ii) 
These meet at the points (0,0), (4?? 1/3
?? 2/3
, 4?? 2/3
?? 1/3
) 
Tangent to (i) at (4?? 1/3
?? 2/3
, 4?? 2/3
?? 1/3
) is ?? . 4?? 2/3
?? 1/3
= 2?? (?? + 4?? 2/3
?? 1/3
) 
Page 5


Solved Examples on Parabola 
Q1: The equation of parabola whose focus is (?? , ?? ) and directrix is ?? ?? -
?? ?? + ?? = ?? , is 
(a) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(b) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(c) (?? ?? + ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
(d) (?? ?? - ?? ?? )
?? - ?????? ?? - ?????? ?? + ?????? = ?? 
Ans: (a)  
Sol: 
 
?? ?? 2
= ?? ?? 2
? (?? - 5)
2
+ (?? - 3)
2
= (
3?? - 4?? + 1
v9 + 16
)
2
 ? 25(?? 2
+ 25 - 10?? + ?? 2
+ 9 - 6?? )
 = 9?? 2
+ 16?? 2
+ 1 - 12???? + 6?? - 8?? - 12????
 ? 16?? 2
+ 9?? 2
- 256?? - 142 ?? + 24???? + 849 = 0
 ? (4?? + 3?? )
2
- 256?? - 142 ?? + 849 = 0
 
Q2: The point on the parabola ?? ?? = ?? ?? . Whose distance from the focus is 8 , 
has ?? -coordinate as 
(a) 0 
(b) 2 
(c) 4 
(d) 6 
Ans: (d)  
Sol: If ?? (?? 1
, ?? 1
) is a point on the parabola ?? 2
= 4???? and S is its focus, then ???? =
?? 1
+ ?? 
Here 4?? = 8 ? ?? = 2; ???? = 8 
? 8 = ?? 1
+ 2 ? ?? 1
= 6 
Q3: If the parabola ?? ?? = ?? ax passes through (-?? , ?? ), then length of its latus 
rectum is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) 4 
Ans: (c) 
Sol: The point (-3,2) will satisfy the equation ?? 2
= 4???? ? 4 = -12?? ? Latus 
rectum = 4|?? | = 4 × |-
1
3
| =
4
3
 
Q4: The equation of the parabola with its vertex at the origin, axis on the ?? -
axis and passing through the point (?? , -?? ) is 
(a) ?? ?? = ???? ?? + ?? 
(b) ?? ?? = ???? ?? 
(c) ?? ?? = -???? ?? 
(d) ?? ?? = -???? ?? + ?? 
Ans: (c) 
Sol: Since the axis of parabola is ?? -axis with its vertex at origin. 
? Equation of parabola ?? 2
= 4???? . Since it passes through (6, -3) ; 
? 36 = -12?? ? ?? = -3 
? Equation of parabola is ?? 2
= -12?? . 
Q5: The line ?? - ?? = ?? is the directrix of the parabola ?? ?? - ???? + ?? = ?? . Then 
one of the values of ?? is 
(a) 
?? ?? 
(b) 8 
(c) 4 
(d) 
?? ?? 
Ans: (c)  
Sol: The parabola is ?? 2
= 4
?? 4
(?? -
8
?? ). Putting ?? = ?? , ?? -
8
?? = ?? . The equation is 
?? 2
= 4 ·
?? 4
· ?? 
? The directrix is ?? +
?? 4
= 0 i.e., ?? -
8
?? +
?? 4
= 0. But ?? - 1 = 0 is the directrix. So 
8
?? -
?? 4
= 1 ? ?? = -8,4 
Q6: The ends of a line segment are ?? (?? , ?? ) and ?? (?? , ?? ). ?? is a point on the 
line segment ???? such that ???? : ???? = ?? : ?? . If ?? is an interior point of the 
parabola ?? ?? = ?? ?? , then 
(a) ?? ? (?? , ?? ) 
(b) ?? ? (-
?? ?? , ?? ) 
(c) ?? ? (
?? ?? ,
?? ?? ) 
(d) None of these 
Ans: (a)  
Sol:  ?? = (1,
1+3?? 1+?? ) It is an interior point of ?? 2
- 4?? = 0 iff (
1+3?? 1+?? )
2
- 4 < 0 
? (
1 + 3?? 1 + ?? - 2) (
1 + 3?? 1 + ?? + 2) < 0 ? (
?? - 1
1 + ?? ) (
5?? + 3
1 + ?? ) < 0 ? (?? - 1)(?? +
3
5
) < 0 
Therefore, -
3
5
< ?? < 1. But ?? > 0 ? 0 < ?? < 1 ? ?? ? (0,1). 
Q7: The equation of the tangent to the parabola ?? ?? = ???? ?? , which is 
perpendicular to the line ?? = ?? ?? + ?? is 
(a) ?? - ?? ?? + ?? = ?? 
(b) ?? ?? - ?? + ???? = ?? 
(c) ?? ?? + ?? - ???? = ?? 
(d) ?? ?? + ?? + ???? = ?? 
Ans: (a)  
Sol: A line perpendicular to the given line is 3?? + ?? = ?? ? ?? = -
1
3
?? +
?? 3
 
Here ?? = -
1
3
, ?? =
?? 3
. If we compare ?? 2
= 16?? with ?? 2
= 4???? , then ?? = 4 
Condition for tangency is ?? =
?? ?? ?
?? 3
=
4
(-1/3)
? ?? = -36 … Required equation is 
?? + 3?? + 36 = 0. 
Q8: Two tangents are drawn from the point (-?? , -?? ) to the parabola ?? ?? =
?? ?? . If ?? is the angle between these tangents, then tan ?? = 
(a) 3 
(b) ?? /?? 
(c) 2 
(d) ½ 
Ans: (a) 
Sol: Equation of pair of tangent from (-2, -1) to the parabola is given by SS
1
=
?? 2
 i.e. (?? 2
- 4?? )(1 + 8) = [?? (-1) - 2(?? - 2)]
2
 
 ? 9?? 2
- 36?? = [-?? - 2?? + 4]
2
? 9?? 2
- 36?? = ?? 2
+ 4?? 2
+ 16 + 4???? - 16?? - 8?? ? 4?? 2
- 8?? 2
+ 4???? + 20?? - 8?? + 16 = 0
 ? tan ?? = |
2vh
2
- ????
?? + ?? | = |
2v4 - 4(-8)
4 - 8
| = |
12
-4
| = 3
 
Q9: If (
?? ?? )
?? /?? + (
?? ?? )
?? /?? =
v?? ?? , then the angle of intersection of the parabola ?? ?? =
?? ???? and ?? ?? = ?? ???? at a point other than the origin is 
(a) ?? /?? 
(b) ?? /?? 
(c) ?? /?? 
(d) None of these 
Ans: (b) 
Sol: 
Given parabolas are ?? 2
= 4????   … ..(i) and ?? 2
= 4????    …… (ii) 
These meet at the points (0,0), (4?? 1/3
?? 2/3
, 4?? 2/3
?? 1/3
) 
Tangent to (i) at (4?? 1/3
?? 2/3
, 4?? 2/3
?? 1/3
) is ?? . 4?? 2/3
?? 1/3
= 2?? (?? + 4?? 2/3
?? 1/3
) 
Slope of the tangent (?? 1
) =
2?? 4?? 2/3
?? 1/3
=
?? 1/3
2?? 1/3
 
Tangent to (ii) at (4?? 1/3
?? 2/3
, 4?? 2/3
?? 1/3
) is ?? · 4?? 1/3
?? 2/3
= 2?? (?? + 4?? 2/3
?? 1/3
) 
Slope of the tangent (?? 2
) =
2?? 1/3
?? 1/3
 
If ?? is the angle between the two tangents, then ? tan ?? = |
?? 1
-?? 2
1+?? 1
?? 2
| =
|
?? 1/3
2?? 1/3
-
2?? 1/3
?? 1/3
1+
?? 1/3
2?? 1/3
·
2?? 1/3
?? 1/3
| 
=
3
2
·
1
(
?? ?? )
1/3
+ (
?? ?? )
1/3
=
3
2
·
1
v3
2
= v3; ? ?? = 60
°
=
?? 3
 
Q10: The equation of the common tangent touching the circle (?? - ?? )
?? +
?? ?? = ?? and the parabola ?? ?? = ?? ?? above the ?? -axis, is 
(a) v?? ?? = ?? ?? + ?? 
(b) v?? ?? = -(?? + ?? ) 
(c) v?? ?? = ?? + ?? 
(d) v?? ?? = -(?? ?? + ?? ) 
Ans: (c) 
Sol:  
 
Any tangent to ?? 2
= 4?? is ?? = ???? +
1
?? . It touches the circle if 3 = |
3?? +
1
?? v1+?? 2
| or 
9(1 + ?? 2
) = (3?? +
1
?? )
2
 or 
1
?? 2
= 3, ? ?? = ±
1
v3
 
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FAQs on Solved Examples: Parabola - Mathematics (Maths) for JEE Main & Advanced

1. What is a parabola in mathematics?
Ans. A parabola is a U-shaped curve that can be represented by a quadratic equation of the form y = ax^2 + bx + c. It is a conic section formed by the intersection of a plane parallel to the side of a cone.
2. How do you find the vertex of a parabola?
Ans. The vertex of a parabola can be found using the formula x = -b/2a, where the x-coordinate of the vertex is -b/2a. To find the y-coordinate, substitute the x-coordinate back into the equation of the parabola.
3. What is the focus of a parabola?
Ans. The focus of a parabola is a fixed point located on the axis of symmetry of the parabola. It is equidistant from the directrix as it is from any point on the parabola.
4. How do you determine if a parabola opens upwards or downwards?
Ans. The direction in which a parabola opens is determined by the sign of the coefficient of x^2 in the equation. If the coefficient is positive, the parabola opens upwards; if it is negative, the parabola opens downwards.
5. What is the axis of symmetry of a parabola?
Ans. The axis of symmetry of a parabola is a vertical line that passes through the vertex of the parabola. It divides the parabola into two symmetrical halves. The equation of the axis of symmetry is x = -b/2a.
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Solved Examples: Parabola | Mathematics (Maths) for JEE Main & Advanced

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Solved Examples: Parabola | Mathematics (Maths) for JEE Main & Advanced

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Solved Examples: Parabola | Mathematics (Maths) for JEE Main & Advanced

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