Question #7f620

1 Answer
Apr 30, 2017

(a)

f(1,2)=<2xy,x+2y>(1,2)=<4,5>

(b)

We can do this many ways. But if we agree in differential terms that for a level curve:

df=fydy+fxdx=0

Then:

dydx=fxfy, the implicit function theorem

And this means that:

dydx=2xyx+2y=45

So we say that:

y=mx+c=45x+c

And we plug in a value, (1,2), so that: y=25(2x+7)

(c)

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