2. Partial Differentiation - MIT OpenCourseWare

2. PARTIAL DIFFERENTIATION 1 b) wx = −y2/x2, wy = 2y/x; therefore at (1,2,4), we get wx = −4, wy = 4, so that the tangent plane is w = 4−4(x −1)+4(y −2), or w = −4x +4y. x x y 2B-2 a) zx = = ; by symmetry (interchanging x and y), zy = ; then the x2 + y2 z z tangent plane is z = z0 0+ x0 (x−x y0 x0 x+ y0 y , since x2+y2 = z2. 0)+ (y−y0), or z = ................
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