Help me please :( Find the points where the line x + 2y = 4 cuts the parabola y = (x − 1)^2, and show that the line is the normal to the curve at one of these points.
Okie dokie, what is the definition of a line being normal to a curve? Write it out here so as to get everyone on the same page
when m1 m2 = -1?
where m1 and m2 are gradients?
What's the gradient of each curve?
its 2x-2 and - 1/2
2x-2 is the gradient of (x-1)^2 in general, but what is the gradient of the curve at the point of intersection?
gradient is 2
Good, now we just need to verify that \[m _{1}m _{2} = -1\] Let us define \[m_{1} = 2\] and \[m _{2}=-\frac{ 1 }{ 2 }\] Take it from there
The line intersects the parabola at (2,1) and at (-1/2,9/4). The former is the one where it is normal to the curve.
ok.. so the -1/2 is the one that is the normal?
Former is the earlier one, latter is the later one
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