parametrization of the left half of y = x^2 - 4x + 3

tsh44

Junior Member
Joined
Sep 4, 2005
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Hi I need to find the parametrization for the left half of the parabola

. . .y = x^2 - 4x + 3

How do you change regular equations into parametric ones? And how would I find the equationf for only the left half?
 
I think this is what you want, but not sure

y=x^2 -4x +3 complete the square by adding and subtracting 1/2 the x
terms coefficient squared
y=[x^2-4x+4]-4+3 combine terms and factor
y=[x-2]^2-1 rewrite
[y+1] =[x-2]^2 a parabola, open up vertex at 2,-1
axis of symmetry x=2

the equation of left 1/2 would be all points x<2 y=[x-2]^2-1

I think this is what you need.
 
tsh44 said:
i think i need x= and y = equations
In terms of what parameters?

Please reply with all the information for this exercise, along with whatever you have tried thus far. Thank you.

Eliz.
 
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