MedVision ad

Locus: Help please (1 Viewer)

Jkitty

Member
Joined
Apr 15, 2014
Messages
35
Gender
Female
HSC
2015
3. Find the point of intersection between the
i. tangent
Ii. Normal to the curve
A. x^2=4y at the points (2p,p^2) and 2q,q^2)


Thank you :)
 

braintic

Well-Known Member
Joined
Jan 20, 2011
Messages
2,137
Gender
Undisclosed
HSC
N/A
That is just bookwork. It should be in your notes. Or look in the textbook.
 

Jaguar33

Member
Joined
Mar 29, 2014
Messages
36
Gender
Female
HSC
2015
i found out how to do it! Right, so first for i) tangent,

1. You differentiate x^2=4y, which will give you a gradient of p.
2. Use the equation formula (y-y1)=m(x-x1)
and place the first points in (2p, p^2)
this will give you an equation of y=px - p^2

Then do this step again, except with the other points (2q,q^2)
and you will get y=qx-q^2

Make the two equations you have found, and make them equal each other. Then proceed, to put any terms with x on the left side, and the other on p side,
Then factorise
So it will look like this by now
x(p-q) = p(p-q)(p+q)
cross out, then you have the first point of intersection for x= p +q. Then sub this back in to get why

and i havent done the 2nd part, but im guessing u do the same for the normal :)
 

Jkitty

Member
Joined
Apr 15, 2014
Messages
35
Gender
Female
HSC
2015
i found out how to do it! Right, so first for i) tangent,

1. You differentiate x^2=4y, which will give you a gradient of p.
2. Use the equation formula (y-y1)=m(x-x1)
and place the first points in (2p, p^2)
this will give you an equation of y=px - p^2

Then do this step again, except with the other points (2q,q^2)
and you will get y=qx-q^2

Make the two equations you have found, and make them equal each other. Then proceed, to put any terms with x on the left side, and the other on p side,
Then factorise
So it will look like this by now
x(p-q) = p(p-q)(p+q)
cross out, then you have the first point of intersection for x= p +q. Then sub this back in to get why

and i havent done the 2nd part, but im guessing u do the same for the normal :)
Thank you so much :)
 

braintic

Well-Known Member
Joined
Jan 20, 2011
Messages
2,137
Gender
Undisclosed
HSC
N/A
You should be asking your teacher why they haven't given you an example of this in class.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top