Help finding an equation for the level curve

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To find the equation for the level curve of the function f(x, y) = (x^2 + y^2)e^(xy) at the point P(1,0), the correct approach is to evaluate f(1,0), which results in f(1,0) = e. The level curve is then defined by the equation (x^2 + y^2)e^(xy) = e. The initial attempt to set the function to zero was incorrect, as level curves represent constant values rather than zero. Converting to polar coordinates may simplify the equation further, but the key is to ensure that the function equals e for all points on the curve.
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Hey guys, I tried it out, but I just don't get it. I have to find the equation for the level curve f(x, y)=(x^2 + y^2)e^(xy); that contains the point P(1,0). By the way, e^(xy) is read e to the x times y, just in case.


What I did, which looks wrong the whole way was:

(x^2 + y^2)e^(xy) ---> (x^2)(e^(xy)) + (y^2)(e^(xy)) = 0

---> ln(x^2) + ln(e^(xy)) = (-1) ln(y^2) + ln(e^(xy))
---> 2ln(x) + xy = (-1) (2ln(y) + xy)
---> 2ln(x) = (-1)(2ln(y))


...and I'm stuck there. Could anyone help correct this, or if possible, help continue? Thanks a bunch.
 
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I thought that the equation you need to solve would be written as:

f(x,y) = f(1,0)

Or

(x^2+y^2)e^{xy} = e

From here, my instinct would be to convert to polar coordinates.

Carl
 
SigmaCrisis said:
I have to find the equation for the level curve f(x, y)=(x^2 + y^2)e^(xy); that contains the point P(1,0).

What I did, which looks wrong the whole way was:

(x^2 + y^2)e^(xy) ---> (x^2)(e^(xy)) + (y^2)(e^(xy)) = 0
...

Why did you write that

f(x,y)=(x^2+y^2)e^{xy}=0?

You want a level curve. That means that f(x,y) is the same for all points of the curve.The level curve should contain the point with x=1, y=0. Plug in these values and see what you get for f(x,y).

ehild
 
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