# find slope

• Feb 13th 2007, 05:09 AM
Aussieboy
find slope

the slope of the given points:
1.) (3/4 , -2) ; (2 , 2/3)
2.) (0 , 2/3) ; (3 , 0)

the equation of the line with two given points:

1.) (3/4 , 0) ; (0 , 4/3)
2.) (3/5 , 2) ; (5 , 2/3)

thanks, ;-)
• Feb 13th 2007, 05:43 AM
topsquark
Quote:

Originally Posted by Aussieboy

the slope of the given points:
1.) (3/4 , -2) ; (2 , 2/3)
2.) (0 , 2/3) ; (3 , 0)

The slope of a line is given by the formula:
m = (y2 - y1)/(x2 - x1)

So for problem 1:
m = (2/3 - -2)/(2 - 3/4) = (2/3 + 2)/(2 - 3/4) = (2/3 + 6/3)/(8/4 - 3/4) = (8/3)/(5/4) = 32/15

You do the second one. I get m = -2/9.

-Dan
• Feb 13th 2007, 05:51 AM
topsquark
Quote:

Originally Posted by Aussieboy
the equation of the line with two given points:

1.) (3/4 , 0) ; (0 , 4/3)
2.) (3/5 , 2) ; (5 , 2/3)

A standard for the form of a line is the slope-intercept form:
y = mx + b
where m is the slope of the line and b is the y-intercept: the point (0, b).

For the first problem we have a slope of:
m = (4/3 - 0)/(0 - 3/4) = (4/3)/(-3/4) = -16/9

So we know that the line is of the form:
y = -(16/9)x + b

Consider our first point on this line: (3/4, 0). Inserting this point into our line equation gives us:
0 = -(16/9)(3/4) + b

Solving for b:
0 = -(4/3) + b
b = 4/3

Thus the line is
y = -(16/9)x + (4/3)

You do the second one. I get that y = -(10/33)x + (24/11)

-Dan