The line y = mx + c intersects the parabola la y^2= 4ax at the points P and Q.Show that the coordinates of the mid-point of PQ is ((2a-mc)/(m^2), (2a)/m) If the mid-point is M, find the locus of M whenm varies and c = 1

Jadon Melendez

Jadon Melendez

Answered question

2022-07-27

The line y = mx + c intersects theparabola y 2 = 4 a x at the points P and Q.Show that the coordinates of the mid-point of PQ is ( 2 a m c m 2 , 2 a m ).
If the mid-point is M, find the locus of M whenm varies and c = 1

Answer & Explanation

losnonamern

losnonamern

Beginner2022-07-28Added 12 answers

y=mx+c eqn (1)
y 2 = a x eqn (2)
Square both side eqn 1
will get
y 2 = m 2 x 2 + 2 m c x + c 2 ... (3)
set 2 and 3 equals
4 a x = m 2 x 2 + 2 m c x + c 2
or
( m 2 ) x 2 + ( 2 m c 4 a ) x + ( c 2 ) = 0
x = b 2 a = ( 2 m c 4 a ) 2 m 2 = 2 a m c m 2
now plug in function 1
y = m ( 2 a m c m 2 ) + c = 2 a m c m + c m m = 2 a m
so we just showed that it works
( 2 a m c m 2 , 2 a m )
next,
when c=1:
( 2 a m m 2 , 2 a m )

Do you have a similar question?

Recalculate according to your conditions!

New Questions in Elementary geometry

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?