maths ext 1 help (1 Viewer)

[viraj30]

can some1 show me the working out of this question..

find, from the first principles, the equation of the chord joining-
(a) t1= 2, t2= -1 on x= 2t, y= t^2

This is from parametric representation of parabola...Thanx

 

[viraj30]

i asked for help..not for retards

 

[viraj30]

well thanx for joining me retard

 

[bleakarcher]

gtfo finance, stupid fuking troll. sorry btw buddy, i cant answer this question

 

[bleakarcher]

i cbf by first principle lol

 

[nightweaver066]

Sub one of the t values first.

I"ll use t = 2 first. When t = 2,

x = 2(2) = 4
y = (2)^2 = 4

Now you have obtained a point (4, 4)

Doing the same thing with the other t value, t = -1. When t = -1,

x = 2(-1) = -2
y = (-1)^2 = 1

Point is (-2, 1)

Now find the gradient between the two points.

m = (4-1)/(4+2)
= 1/2

Using point gradient formula,
y -1 = (x + 2)/2
2y - 2 = x + 2
x - 2y + 4 = 0

 

[viraj30]

well im in year 10 tryin to do questions from my bro's book...the book says maths ext 1

 

[bleakarcher]

^that is wat i had in mind, but it says by first principle which is a lolwut?

 

[viraj30]

Sub one of the t values first.

I"ll use t = 2 first. When t = 2,

x = 2(2) = 4
y = (2)^2 = 4

Now you have obtained a point (4, 4)

Doing the same thing with the other t value, t = -1. When t = -1,

x = 2(-1) = -2
y = (-1)^2 = 1

Point is (-2, 1)

Now find the gradient between the two points.

m = (4-1)/(4+2)
= 1/2

Using point gradient formula,
y -1 = (x + 2)/2
2y - 2 = x + 2
x - 2y + 4 = 0

you are da man!

 

[apollo1]

x-2y+4 = 0

 

[nightweaver066]

well im in year 10 tryin to do questions from my bro's book...the book says maths ext 1

Read the examples prior to the questions. They will run you through how to approach and solve these questions.

 

[bleakarcher]

u r a gennius

this community is fuked wif trollz

 

[viraj30]

im sure it says 'working out' thnx anyways

 

[Deep Blue]

can some1 show me the working out of this question..

find, from the first principles, the equation of the chord joining-
(a) t1= 2, t2= -1 on x= 2t, y= t^2

This is from parametric representation of parabola...Thanx

Basically sub in the values t=2 and t=-1 to get two pairs of co-ordinates. Then enter those co-ordinates into this formula to get the equation of the chord.

 

[viraj30]

^ well its a question sheet..no examples shown

 

[someth1ng]

I was worried with the "first principles" part...I was like "WTF, SHIT" then I realised that someone else solved like how I would have solved it.