GPREP1-Slope

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GPREP1-Slope

by medea66 » Tue Aug 12, 2008 8:06 pm
1 I can understand, but is 2 insufficient b/c there are few lines w/ different slopes that can meet the criteria and intersect @ the given point?
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by amitansu » Tue Aug 12, 2008 9:07 pm
To know the slope we need to know the two coordinate points of each line.
With the help of both setms we can get this.

Amit

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by medea66 » Wed Aug 13, 2008 6:25 pm
Oh yes, that is the definition of slope, change in y/change in x.

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by medea66 » Wed Aug 13, 2008 6:30 pm
.........but I'm assuming you used a drawing to answer the question instead of getting the actual slope. So, if the Y-int of one line is greater than than of the other line, the line with the greater y-int is steeper and has a higher slope?

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by amitansu » Wed Aug 13, 2008 8:53 pm
True, a line with higher slope gets steeper...
but i didn't use any drawing or graph.

When two stems need to be combined, then we just need to see whether
the ans is achievable.

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by kiran.raze » Thu Aug 14, 2008 9:31 am
Hi Medea,

Well, I guess you are right - a line with higher y intercept would have an obtuse angle with the X axis (as it lies in the first quadrant)i.e a negative slope(change in Y/change in X=tan(angle made by the line with the x axis)as tan(obtuse angle(90<x<180) ='-'. And any line intersecting this line at (5,1) will either have an angle greater than than the angle made by N when obtuse(i.e >90) or any angle between 0 & 90 , and in both these cases the Tan of the angle would be > than the one made by N

therefore we can say that the slope of N would be less than the line P when the intersection point is (5,1) & N is the line which makes a higher Y intercept.

thanks,
Kiran

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by sumithshah » Thu Aug 14, 2008 10:50 am
I have a slightly algbric approach.

For each line we can say :

Line N:
y-y1 = M (x-x1) --> equation of a st line

using 5,1

y-1 = M ( x - 5)

or y = Mx - (5M+1)

Line P:
y-y1 = m (x-x1) --> equation of a st line

using 5,1

y-1 = m ( x - 5)

or y = mx - (5m+1)

Using statement 2 we know

Y intercept of N is greater than that of P
hence from the weird stuff done in statement one we can say

-(5M+1) > - (5m+1)

hence you can get the ratio of M/m or m/M ---> Solvable.