Help - differentiation related (1 Viewer)

[Petinga]

Find the equations of the tangent to the parabola y = 4x - 3x squared at the points where the parabola cuts the x axis


How do i find out the points were the parabola cuts the x axis or even y axis??????

 

[stella8h8chang]

I suck mighty crap at typing maths out but anyway...

When the parabola cuts the x axis, the y value is zero. So you do
0 = 4x - 3x^2 and solve it, ie
0 = x(4-3x)
x = 0 or x = 4/3

When the parabola cuts the y axis, the x value is zero.

Now you plug these values into the derivative and keep going. Hope I helped.