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Galaxay1
21-10-2007, 02:19 PM
http://img139.imageshack.us/img139/483/pkfpems0.png (http://imageshack.us)

Question:

By using gradients find the value of K.

VPSwow
21-10-2007, 02:26 PM
Wow i just done maths higher and never had a question like this or even been tought this.

-:Undertaker:-
21-10-2007, 02:27 PM
You know, I have no idea why they teach us useless crap like this.

HOW will this graph help us in later life?

Galaxay1
21-10-2007, 02:28 PM
Idk but i need the answer :S

Wizzdom
21-10-2007, 02:29 PM
You know, I have no idea why they teach us useless crap like this.

HOW will this graph help us in later life?

To find gradients which are sometimes missing?

It was like 2 years ago since i have done this, so i cant help you as i have forgotten. Sorry!

Ostinato
21-10-2007, 03:41 PM
I managed to get an answer but it is completely wrong... lol.

I got a Higher B in maths and honestly you will not get a question as difficult as this - I think it's hard due to the lack of information given.

Also - how accurate is your diagram? Is it supposed to be a right angle?

My current answer is:-

k = -9x + 29 over 4

Lol it is most likely wrong but it makes sense in the terms I have done it...

Galaxay1
21-10-2007, 04:16 PM
its a right angle yeh thats why i put the little angel thing in :P

VPSwow
21-10-2007, 04:20 PM
If it was the correct shape to the question i may be able to help, but from that i cannot tell if the triangles are scaline or equalateral ect.

Ostinato
21-10-2007, 04:40 PM
I'VE GOT IT :)

Lol right...

First of all you find the gadient of QP, which = 1/2 and as PQR is 90degrees you can state that the gradient of QR is therefore -2 (perpendicular).

You then have the gradient of the line QR and you have the point Q so you just find the equation of that line - which is y= -2x + 10.

You then substitute the point R into the equation of the line so you have:-

k = -2(5) + 10
k = -10 + 10
k = 0 :)

VPSwow
21-10-2007, 04:44 PM
I'VE GOT IT :)

Lol right...

First of all you find the gadient of QP, which = 1/2 and as PQR is 90degrees you can state that the gradient of QR is therefore -2 (perpendicular).

You then have the gradient of the line QR and you have the point Q so you just find the equation of that line - which is y= -2x + 10.

You then substitute the point R into the equation of the line so you have:-

k = -2(5) + 10
k = -10 + 10
k = 0 :)

That kids got it :) +REP

Ostinato
21-10-2007, 04:46 PM
That kids got it :) +REP

Kid? :o

VPSwow
21-10-2007, 04:47 PM
Kid? :o

Kid/ Adult i dno what you are :P

Ontopic - Well done at working it out :)

Ostinato
21-10-2007, 10:09 PM
Kid/ Adult i dno what you are :P

Ontopic - Well done at working it out :)

Lol tar :)

PTER
21-10-2007, 10:31 PM
um, i dont understand how k = 0 when from the picture, it clearly doesnt lol. unless that picture isnt right,

Ostinato
21-10-2007, 10:48 PM
um, i dont understand how k = 0 when from the picture, it clearly doesnt lol. unless that picture isnt right,

Pmsl hmmm...

PTER
22-10-2007, 12:09 AM
what i can find is

QP m = 2/3

y = 2/3x + b
7 = 2/3(-3) + b
7 = -2 + b
b = 7 + 2
b = 9

y = 2/3x + 9


QR since it is perpendicular with QP, its slope would be m = -1.5

y = -1.5x + b
7 = -1.5(-3) + b
7 = 4.5 + b
b = 2.5

y = -1.5x + 2.5

substituting the given value, 5 into the second equation, you'll have

-1.5(5) + 2.5 = k
-7.5 + 2.5 = k
k = -5


and i dont know gradients, sorry

Jõnathan
22-10-2007, 09:30 AM
I'VE GOT IT :)

Lol right...

First of all you find the gadient of QP, which = 1/2 and as PQR is 90degrees you can state that the gradient of QR is therefore -2 (perpendicular).

You then have the gradient of the line QR and you have the point Q so you just find the equation of that line - which is y= -2x + 10.

You then substitute the point R into the equation of the line so you have:-

k = -2(5) + 10
k = -10 + 10
k = 0 :)
Lol that can't be right - the point R isn't on 0 :)
I think that PTER's right.

Galaxay1
22-10-2007, 12:03 PM
what i can find is

QP m = 2/3

y = 2/3x + b
7 = 2/3(-3) + b
7 = -2 + b
b = 7 + 2
b = 9

y = 2/3x + 9


QR since it is perpendicular with QP, its slope would be m = -1.5

y = -1.5x + b
7 = -1.5(-3) + b
7 = 4.5 + b
b = 2.5

y = -1.5x + 2.5

substituting the given value, 5 into the second equation, you'll have

-1.5(5) + 2.5 = k
-7.5 + 2.5 = k
k = -5


and i dont know gradients, sorry

k is -5 :P

Ostinato
22-10-2007, 10:10 PM
woteva gurlfriend

Naruto!
22-10-2007, 10:14 PM
woteva gurlfriend
Don't give in!!

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