Find the equation of the parabola that satisfies the following conditions: Focus (0, –3); directrix y = 3

0 votes
15 views
asked Feb 9, 2018 in Mathematics by Rohit Singh (61,782 points) 35 133 356
Find the equation of the parabola that satisfies the following conditions: Focus (0, –3); directrix y = 3

1 Answer

0 votes
answered Feb 9, 2018 by sameer (82,980 points) 5 11 37

Focus = (0, –3); directrix y = 3
Since the focus lies on the y-axis, the y-axis is the axis of the parabola.
Therefore, the equation of the parabola is either of the form x2 = 4ay or x2 = – 4ay.
It is also seen that the directrix, y = 3 is above the x-axis, while the focus (0, –3) is below the x-axis. Hence, the parabola is of the form x2 = –4ay.
Here, a = 3
Thus, the equation of the parabola is x2 = –12y.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

One Thought Forever

“There is a close connection between getting up in the world and getting up in the morning.“
– Anon
~~~*****~~~

...