Mathematics 103, Section 208, Final Review April 8, 2013 Pooya Ronagh (pooya@math.ubc.ca) Problem 1. Write a left and a right Riemann sum for b ∫ x2 dx b and ∫ a x3 dx a and evaluate them. 1 Problem 2. Calculate using Riemann sums: ∫0 ex dx Problem 3. Evaluate 2b/n + 22b/n + ⋯ + 2(n−1)b/n + 2nb/n n→∞ n lim 3 4 1/8 ∫ x (1 − 12x ) dx ∫ 5 ∫ ln x dx x t1/2 ln(2t)dt 1 dx ∫ x ln x cos x dx ∫ sin3 x n 3 23 lim ∑ (1 + i. ) n→∞ n n i=1 x dx ∫ x + 10 5 ∫ t1/2 ln(t)dt 1 √ 8 + 9xdx ∫ 9 ∫ sec x tan xdx 6 2 ∫ tan x sec xdx 2b 3 − 5 + 7 − 9 + 11 − ⋯ − 81 2 ∫ (3x + 5)n dx 0 ∫ x2 + 2x + 3 dx (x + 1)(x + 2)(x + 3) π sin x dx ∫ 0 (2 + cos(x))3 xdx + b2 b 1+ε 1 1 √ lim ∫ dt ε→0 ε 1 1 + t4 √ e ln x dx ∫ x 1 19 dx ∫ 2 18 x − 34x + 289 ∫ x2 Problem 4. Prove V = Sh/3 for a pyramid with (a) a square base, (b) a circular base, (c) a shape as base! Here S denotes the area of the base. (Hint: you need to use the fact that if you rescale an object by a factor of s, the area also rescales by a factor of s2 .) √ x Problem 5. Show that y(x) = ∫0 1 − t2 dt satisfies the differential equation y ′ y ′′ = −x; y ′ (0) = 1 y(0) = 0, Problem 6. Let a > 0. Show that over positive x-axis, x ∫ 0 √ dt √ = ln(x + x2 + a2 ) − ln a t2 + a2 Find c such that x ∫ c √ dt √ = ln(x + x2 + a2 ). t2 + a2 x Problem 7. If f (x) is continuous, find f (π/2) if ∫0 f (t)dt = 2x(sin x + 1). Solve the same x/2 problem if ∫0 f (t)dt = 2x(sin(x) + 1). Problem 8. Find the area between y = 4 − x2 , x = y 2 − 4y, y = 3x x = 2y − y 2 . Problem 9. Find area under y = 1 − x2 in two ways. Problem 10. Find volume of solid of revolution of the region bounded by y = 2ax − x2 , y = 0 about both coordinate axis √ y = ax, y = 2, x = a about both coordinate axis y = (x − 1)2 , y = (x + 1)2 , y = 0 about both coordinate axis y = ex , y = 2, x = 0, about y = −1. Problem 11. Find average distance from a point on the perimeter of a square of side length a to the center. Find the average of the square of the distance. Problem 12. Find arclength y = 5x + 2, 0 ≤ x ≤ 1 y = x3/2 , 0 ≤ x ≤ 1 y = (ex + e−x )2, 0 ≤ x ≤ b x = t2 , y = t3 , 0 ≤ t ≤ 2 x2 /a2 + y 2 /b2 = 1 Problem 13. Solve the following differential equations and initial value problems dy = (2x + 5)4 dx dy 1 = dx y + 1 dy = xy 2 dx cos x sin y dy = sin x dx, Problem 14. Find y(5) if y satisfies dy dx = x2 y −1 , y(0) = 0 y(0) = 10. Problem 15. If X1 and X2 have uniform distribution between zero and 2, Let X = X1 +X2 . Find the distribution, mean, median and variance of X. Problem 16. A point is chosen randomly (and uniformly) on a unit circle in the plane. Find the distribution of the projection of this point on the x-axis. Find its expected value (i.e. mean). Problem 17. A router receives two types of request from client computers with exponential distributions X1 and X2 of respective parameter λ1 and λ2 . Find the distribution in time for the stand-by type of the router. (Hint: For intervals I and J on the real line we may assume P (X1 ∈ I and X2 ∈ J) = P (X1 ∈ I).P (X2 ∈ J).) Problem 18. Determine value of the improper integral if it converges or prove that it diverges: ∞ ∫ 1 ∞ sin(x)dx ∫ 0 ∞ ∫ 1 π/4 dx x ln x tan xdx ∫ −π/2 ∞ ∫ dt t2 − 2t + 1 0 dt √ t t2 − 1 Problem 19. Determine the divergence and convergence of the following series 3n−1 3n+1 n=2 2 ∞ ∑ en n=1 n! ∞ ∑ ∞ ∞ ∞ ∑ ∑ 4 − 3 sin(2n) n2 − 1 n=2 −n2 ∑ ne n=3 √ ∞ nn! ∑ 2 n=10 [(2n)!] n=1 (n4 1 − 1)1/3 Problem 20. Find Taylor series expansion of the following functions, and the interval of their convergence. sin(x)/x, sin(x) + cos(x) Problem 21. Find a 3-rd degree approximation of ln(3/2). Problem 22. Write the Taylor polynomial of degree 5 for ln(x) about a = 1 degree n for cos(x) + 3 about a = 0 degree 4 for y = x2 + x − 1 about origin (a = 0) degree 4 for y = x2 + x − 1 about x = 10.