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Chapter 2 / Textbook 2.4, Example 2

« on: September 23, 2020, 03:08:07 PM »

In Example 2, we have that f(x,y) = (3x^2+4x+2)/2(y-1). How do we come from that, to get that it's partial derivative  ∂f/∂y(x,y) = -(3x^2+4x+2)/2(y-1)^2, as shown in the picture.

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Chapter 2 / Lec 0101 - 9/15 Question

« on: September 20, 2020, 06:16:36 PM »

I had a question from the lecture about the Methods for solving a differential equation. As indicated in the photo, how do we get u'(sqrt(t^2+1)) = t after plugging in y = u(sqrt(t^2+1)) into the original inhomogeneous equation?