Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
+1 vote
118 views
in Parabola by (91.2k points)
closed by
A tangent to the parabola `y^2=8x` makes an angle of `45^0` with the straight line `y=3x+5.` Then find one of the points of contact.

1 Answer

0 votes
by (94.1k points)
selected by
 
Best answer
The equation of the tangent to the parabola `y^(@)=4ax` at `(at^(2),2at)` is
`ty=x+at^(2)`
Here, a=2. So the equation of the tangent at `(2t^(2),4t)` to the parabola `y^(2)=8x` is
`ty=x+2t^(2)` (1)
The slope of (1) is 1/t and that of the given line is 3. Therefore,
`((1)/(t)-3)/(1+(1)/(t)xx3)=pmtan45^(@)=pm1`
i.e., `t=-(1)/(2)or2`
For t=-1/2, the tangent is `(-(1)/(2))y=x+2((1)/(4))`
i.e., `2x+y+1=0`
and the point of contact is (1/2,-2).
For t=2, the tangent is 2y=x+8 and the point of contact is (8,8).

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.

Categories

...