SOLUTION: The line y=k is a tangent to the parabola y= x^2 -8x +18. a) show this on a diagram b) find the value of k

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: The line y=k is a tangent to the parabola y= x^2 -8x +18. a) show this on a diagram b) find the value of k       Log On


   

Question 1118303: The line y=k is a tangent to the parabola y= x^2 -8x +18.
a) show this on a diagram
b) find the value of k
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
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The line y=k is a tangent to the parabola y= x^2 -8x +18.
a) show this on a diagram
b) find the value of k
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You would be looking for the vertex.

y=x%5E2-8x%2B16%2B18-16, completingthesquare
y=%28x-4%29%5E2%2B2
vertex (4,2)


The tangent line to the parabola at (4,2) is highlight%28y=2%29.

graph%28300%2C300%2C-6%2C6%2C-6%2C6%2Cx%5E2-8x%2B18%2C2%29