Find the domain on which y = x^2 + 8x + 12 is a 1-1 function, and find the inverse function y=f^-1.

how do i find the domain and inverse? thanks!

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- Mar 6th 2010, 01:15 PMbreakdomain of a 1-1 function and its inverse
Find the domain on which y = x^2 + 8x + 12 is a 1-1 function, and find the inverse function y=f^-1.

how do i find the domain and inverse? thanks! - Mar 6th 2010, 01:18 PMMiss
- Mar 6th 2010, 02:08 PMHallsofIvy
Since the graph of that function is a parabola, it will be one to one on the two intervals: x< x-coordinate of vertex and x> x-coordinate of vertex.

You can complete the square to find the vertex.

To find the two inverses, write the equation as $\displaystyle x^2+ 8x+ 12-y= 0$ an use the quadratic formula to solve for x. - Mar 6th 2010, 02:22 PMdrumist
- Mar 6th 2010, 02:42 PMMiss