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the graphs of the equations xy=16 and y=x are drawn on the same set of axes. In which...

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mamawhit | Student | (Level 1) eNoter

Posted January 27, 2011 at 7:56 AM via web

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the graphs of the equations xy=16 and y=x are drawn on the same set of axes. In which quadrant or quadrants will they intersect?

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hala718 | High School Teacher | (Level 1) Educator Emeritus

Posted January 27, 2011 at 8:21 AM (Answer #1)

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Given the curves:

xy =16

Then we will rewrite as a function of x.

==> y= 16/x ...........(1)

And the curve :

y= x...............(2)

We need to find the intersections points .

==> y= y

==> x = 16/x

We will multiply by x.

==> x^2 = 16

==> x = +-4

Then, we have two intersection points at x1= 4 and x2= -4

Now we will find the y-coordinate.

==> y1= x1= 4

==> y2= x2= -4

Then, the points of intersection are :

(4,4) and (-4,-4)

The point (4,4) is located in the first quadrant and the point (-4,-4) is located in the third quadrant.

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