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Kate_xo
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#1
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The straight line y=-2mx-9 is tangent to the curve y=x^2

a) Find the values of m
b) Find the coordinates of the points of contact
c) draw a diagram and explain your answer

Any help will be appreciated
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Indeterminate
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(Original post by Kate_xo)
The straight line y=-2mx-9 is tangent to the curve y=x^2

a) Find the values of m
b) Find the coordinates of the points of contact
c) draw a diagram and explain your answer

Any help will be appreciated
For the first part, note what it means for the line to be a tangent.

You should be able to go from there with (b)
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ztibor
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(Original post by Kate_xo)
The straight line y=-2mx-9 is tangent to the curve y=x^2

a) Find the values of m
b) Find the coordinates of the points of contact
c) draw a diagram and explain your answer

Any help will be appreciated
The line and curve have one comon point.
There x^2=2mx-9 -> x^2+2mx+9=0

This is a quadratic equation with m parameter.
Calculate that m for which the equation gives one root (Discriminat is zero)

Knowing m you can solve the equation for x (point of contact)
or take equal the first derivative of the curve with m and this gives the
meeting point.
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