The line L crosses the x-axis at (-8,0), and the y-axis, forming a triangle of area 16. What is the slope of the line?
What is the slope of the line?
Hello Guest!
If the area of the triangle is 16, the line must intersect the y-axis at 4, because 8*4/2=16.
The slope of the line it 4 : 8 = 0.5
!
The length from the orign to A(8,0) is 8. The formula for the area of a trangle is Area = 1/2 x a x b.
Let the length from the orign to (8,0) be a. To find b we can set 16 = 1/2 x 8 x b, or 16 = 4 x b. So b = 16/4 = 4.
So the length from the orign, along the y-axis to B must be 4, giving us the coordinate B(0,4).
To calculate the slope of a line from A to B we subtract the coordinates of the y-components and divide these by
the diffrence between the coordinates of the x-components, so slope = \(\frac{B_y - A_y}{B_x-A_x} = \frac{4 - 0}{0-8} = \frac{4}{-8} = -\frac{1}{2} = -0.5\)