UNIVERSITY OF DUBLIN TRINITY COLLEGE Faculty of Engineering, Mathematics and Science school of mathematics SF Natural Science SF Human Genetics SF Chemistry with Molecular Modelling SF Physics and Chemistry of Advanced Materials SF Medicinal Chemistry Trinity Term 2010 Module MA22S1 - Sample Paper Dr. D. Kitson Attempt THREE questions. Log tables are available from the invigilators, if required. Non-programmable calculators are permitted for this examination,—please indicate the make and model of your calculator on each answer book used. Page 2 of 3 1. (a) Find the length of the space curve with parametric equations x = sin t − t cos t, y = t2 , z = cos t + t sin t, 0 ≤ t ≤ π (b) Compute the curvature for the smooth space curve with vector equation r(t) = h t3 t2 , , t i, −1 ≤ t ≤ 1 3 2 at the point P (0, 0, 0). (c) Let C be the planar curve with vector equation r(t) = h2t, 4t2 i, −1 ≤ t ≤ 1 Find the centre and radius of the osculating circle at the point P (0, 0). 2. (a) What is the maximum rate of change of the function f (x, y, z) = yexz at the point (0, 1, 2)? Find a scalar equation for the tangent plane to the level surface f (x, y, z) = 1 at (0, 1, 2). (b) Find the critical point(s) of the function f (x, y) = y 2 + 2xy + 4x − 6y + 3 and determine if each critical point is a local maximum, local minimum or saddle point. (c) Use the method of Lagrange multipliers to find the maximum and minimum values that the function f (x, y, z) = 2x + 6y + 10z takes subject to the constraint x2 + y 2 + z 2 = 35. 3. (a) Use the component test to determine if the following vector field is conservative: F(x, y, z) = h y, x, xyz i Page 3 of 3 (b) Compute the line integrals R i. C 2xy ds R ii. C y dx − x dy where C is the circle with centre (0, 0) and radius 2. (c) Find a potential for the vector field F(x, y, z) = h 2xz + y 2 , 2xy, x2 + 3z 2 i and use it to evaluate the line integral Z F · dr C where C is the smooth space curve with vector equation r(t) = h t2 , t + 1, 2t − 1 i, 0 ≤ t ≤ 1. 4. (a) Evaluate the following integral by reversing the order of integration. Z 1Z 1 x e y dy dx 0 x (b) Compute the triple integral ZZZ p x2 + y 2 + z 2 dV E where E is the solid region E = {(x, y, z) ∈ R3 : 1 ≤ x2 + y 2 + z 2 ≤ 4 and z ≥ 0}. (c) Use the transformation (u, v) → (x, y) with x = 2u+v and y = u+2v to evaluate the double integral ZZ 4x − y dA R where R is the region in R2 bounded by the triangle with vertices (0, 0), (1, 2) and (2, 1). c UNIVERSITY OF DUBLIN 2010