need help with appl. calculus (1 Viewer)

[d3vilz]

hey guys, need some help:

Find the equations of the tangents to the parabola y = 6x - x^2 @ the points where the parabola cuts the x-axis.


thanks.

 

[Timothy.Siu]

hey guys, need some help:

Find the equations of the tangents to the parabola y = 6x - x^2 @ the points where the parabola cuts the x-axis.


thanks.

well, first u find where it cuts the x-axis and that is when y=0
so
x(6-x)=0 x=0 and 6
so it cuts at (0,0) and (6,0)
then differentiate
dy/dx=6-2x
x=0 dy/dx=6 and when x=6, dy/dx=-6
so equation of tangents are

y=6x and y=-6(x-6) y=-6x+36