Maths help... :3
@ General forum

So... who wants to? :D

Got a couple of questions that I have tried, but just don't think are right.

First one:

By transforming to rectangular coordinates, identify the curve given in polar coordinates as:

r = 6/ (2- cos theta)

I tried rearranging for r^2, then subbing in x^2 + y^2 and got as far as

2r x^2 - x^3 + 2ry^2 - xy^2 = 6 r, but not sure how to re-arrange it after that.

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2nd question is to do with directional derivatives;

g(x,y,z) = y.x^2 + y.e^z, @ point (-1, 3, 0). I've to find the steepest descent, which is just the negative directional derivative, multiplied by the unit vector.

Is the unit vector found by finding out the magnitude of the point, then basically dividing each point by it?

I've to find the steepest ascent after but will be able to do that after clearing up the above.

Calum McPherson // Caloooomi Posted 1 year ago: Wed, 10 Mar 2010 11:20:56 +0000

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