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Been struggling with this all day. I've got the following situation:

x1*=-x1+x2

x2*=-2x1-x2

Where the 1&2 after the x are subscripts.

Now i can find the equilibrium no trouble: (0,0). I also know, by looking at the eigenvalues that it is a sink.

But how on earth do you sketch it? I've found nullclines:

-x1+x2 = 0

-2x1-x2 = 0

But i cannot, for the life of me, tell which way these lines are going.

Help really appreciated.

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# Help me learn to sketch phase portraits!

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