Very annoying c1 question
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Very annoying c1 question
It says in the mark scheme the coordinates for B = x, 11 - 2x
I used x,y and tried working it out that way, I don't understand where they got 11 - 2x from?
Oh actually I do get where they got it from they got it from the equation of the line, but how is that the y - coordinate?Last edited by IShouldBeRevising_; 12-05-2012 at 17:38. -
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Re: Very annoying c1 questionhmm don't know never come across such a question before(Original post by TenOfThem)
(y-5) = -2(x-3)
y - 5 = 6 - 2x
y = 11 - 2x
I cannot get that you understand this is the line but do not understand that it gives you y -
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Re: Very annoying c1 questionThe equation of the line is(Original post by IShouldBeRevising_)
It says in the mark scheme the coordinates for B = x, 11 - 2x
I used x,y and tried working it out that way, I don't understand where they got 11 - 2x from?
Oh actually I do get where they got it from they got it from the equation of the line, but how is that the y - coordinate?
.
Point B lies on this line, so its coordinates are
We know the coordinates of A, so use the formula we use for finding the distance between 2 points. -
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Re: Very annoying c1 questionYeah I get the method, just didn't know why the y coordinate was 11-2x, but do now.(Original post by raheem94)
The equation of the line is.
Point B lies on this line, so its coordinates are
We know the coordinates of A, so use the formula we use for finding the distance between 2 points.
Btw if you have a straight line with gradient 1 the tangent to this line has gradient -1, does the gradient of the normal to the line also = -1? -
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Re: Very annoying c1 questionIf you have a straight line it can not have a tangent to it(Original post by IShouldBeRevising_)
Yeah I get the method, just didn't know why the y coordinate was 11-2x, but do now.
Btw if you have a straight line with gradient 1 the tangent to this line has gradient -1, does the gradient of the normal to the line also = -1?
If you have a curve with gradient 1 at a given point then the tangent to the curve at that point also has gradient 1
and the gradient of the normal would be -1 -
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Re: Very annoying c1 questionDo we ever draw tangents to straight lines?(Original post by IShouldBeRevising_)
Yeah I get the method, just didn't know why the y coordinate was 11-2x, but do now.
Btw if you have a straight line with gradient 1 the tangent to this line has gradient -1, does the gradient of the normal to the line also = -1? -
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Re: Very annoying c1 questionThe gradient of the normal would be -1.(Original post by IShouldBeRevising_)
Btw if you have a straight line with gradient 1 the tangent to this line has gradient -1, does the gradient of the normal to the line also = -1?
If you did figure out a tangent to a straight line it would have the same gradient as the line. However, tangent to a straight line = straight line so you'd never need to figure that out. -
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Re: Very annoying c1 question(Original post by TenOfThem)
If you have a straight line it can not have a tangent to it
If you have a curve with gradient 1 at a given point then the tangent to the curve at that point also has gradient 1
and the gradient of the normal would be -1
(Original post by raheem94)
Do we ever draw tangents to straight lines?
Yeah just got confused thanks for the help, very speedy service :P(Original post by JamieEclipse)
The gradient of the normal would be -1.
If you did figure out a tangent to a straight line it would have the same gradient as the line. However, tangent to a straight line = straight line so you'd never need to figure that out. -
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Re: Very annoying c1 questionIs the answer (9,-7) and (-3,17) ?(Original post by IShouldBeRevising_)
Yeah just got confused thanks for the help, very speedy service :P -
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Re: Very annoying c1 questionNope(Original post by bong)
Is the answer (9,-7) and (-3,17) ? -
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Re: Very annoying c1 questionlol why what you doing?(Original post by masterhr1)
lol C1. Those were the days... -
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Re: Very annoying c1 questionJanuary 2012(Original post by Buongiorno)
What paper is this question from? -
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Re: Very annoying c1 questionThanks. Edexcel or another exam board?(Original post by IShouldBeRevising_)
January 2012 -
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Re: Very annoying c1 questionwhat were the answers, i got (9,-7) and (-3,17) by setting up a circle centre (3,5) of radius 6root5, and then i sub y=-2x+11 into
(x-3)^2 = (y-5)^2 = 180 to equate the lines and then solved?Last edited by IAmMclovin; 12-05-2012 at 20:39. -
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Re: Very annoying c1 questionyeah, when you draw it, it's a lot easier to see that it's a circle.(Original post by IAmMclovin)
what were the answers, i got (9,-3) and (-7,17) by setting up a circle centre (3,5) of radius 6root5, and then i sub y=-2x+11 into
(x-3)^2 = (y-5)^2 = 180 to equate the lines and then solved?
