Slopes

1.) Using slopes, determine which of the set of three points lie on a straight line:

2.) The line segment drawn from to is perpendicular to the segment drawn from to . Find the value of x.

Thanks a bunch :)

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- Nov 14th 2006, 01:56 AM^_^Engineer_Adam^_^Slopes Help
Slopes

1.) Using slopes, determine which of the set of three points lie on a straight line:

2.) The line segment drawn from to is perpendicular to the segment drawn from to . Find the value of x.

Thanks a bunch :) - Nov 14th 2006, 03:30 AMtopsquark
- Nov 14th 2006, 04:27 AMearboth
Hello,

to 1.) You have three points: A(-1, -2), B(6, -5), C(-10, 2).

If the slope between A and B is the same as the slope between B and C, then the three points lie on a straight line:

s means slope:

Both slopes are not equal therefore the three points don't lie on a straight line.

to 2.) You have 3 points: P(x, 3), Q(4, 1) and B(-5, -6)

a) Calculate the slope between Q and B:

. Thus the perpendicular direction is: -9/7 (have a look at topsquark's post!)

The slope between P and Q should be equal to this perpendicular slope:

. Solve for x.

(I've got x = 22/9)

EB