Series solutions - Bessel's equation, Legendre and Hermite polynomials and their properties - Question Bank

1. Legendre's equation is an example of a second-order linear ordinary differential equation with:
A) Constant coefficients
B) Variable coefficients
C) Regular singular points
D) Irregular singular points
2. The general solution to Bessel's equation of order v can be expressed as y(x) = c1 J_v(x) + c2 Y_v(x). What is the condition for this to be the general solution?
A) v must be an integer
B) v must not be an integer
C) v can be any real number
D) v must be positive
3. What is the value of the integral Integral from -infinity to infinity of exp(-x^2) H_n(x)^2 dx?
A) 2^n n! sqrt(pi)
B) 2^n n! / sqrt(pi)
C) 2^n sqrt(pi) / n!
D) sqrt(pi) / (2^n n!)
4. The Hermite polynomial H_n(x) can be expressed using Rodrigues' formula as:
A) H_n(x) = (-1)^n exp(x^2) * d^n/dx^n (exp(-x^2))
B) H_n(x) = exp(x^2) * d^n/dx^n (exp(-x^2))
C) H_n(x) = (-1)^n * d^n/dx^n (exp(-x^2))
D) H_n(x) = exp(-x^2) * d^n/dx^n (exp(x^2))
5. Which of the following is a correct Rodriguez's formula for Legendre polynomials?
A) P_n(x) = (1/(2^n n!)) * d^n/dx^n (x^2 - 1)^n
B) P_n(x) = (1/(2^n n!)) * d^n/dx^n (x^n - 1)
C) P_n(x) = (1/n!) * d^n/dx^n (x^2 - 1)^n
D) P_n(x) = (1/(2^n)) * d^n/dx^n (x^2 - 1)^n
6. The series solution for Bessel's equation around x=0 typically involves:
A) Power series
B) Fourier series
C) Taylor series
D) Laurent series
7. What is the value of J_1(x) in terms of derivatives of J_0(x)?
A) J_1(x) = -J_0'(x)
B) J_1(x) = J_0'(x)
C) J_1(x) = xJ_0'(x)
D) J_1(x) = (1/x)J_0'(x)
8. Which of the following is NOT a property of Legendre polynomials P_n(x)?
A) P_n(1) = 1
B) P_n(-1) = (-1)^n
C) P_n(x) is an even function if n is even, and odd if n is odd.
D) P_n(0) = 0 for all n
9. The differential equation y'' - 2xy' + 2ny = 0 is Hermite's equation. If we make the substitution x = sqrt(2)u, what does the equation become?
A) u'' - 2u' + 2nu = 0
B) u'' - 2u' + nu = 0
C) u'' - 2u + 2nu' = 0
D) u'' - 2u + nu' = 0
10. What is the relationship between Legendre polynomials and Chebyshev polynomials of the first kind, T_n(x)?
A) They are identical
B) T_n(cos(theta)) = P_n(cos(theta))
C) P_n(cos(theta)) = T_n(cos(theta))
D) They are related via a differentiation
11. Spherical Bessel functions are solutions to the spherical Bessel differential equation: x^2 y'' + 2xy' + [x^2 - n(n+1)]y = 0. They are related to Bessel functions of order n+1/2. What is j_0(x)?
A) sin(x)/x
B) cos(x)/x
C) tan(x)/x
D) cot(x)/x
12. What is the asymptotic behavior of J_v(x) for large x?
A) J_v(x) approx sqrt(2/(pi*x)) * cos(x - v*pi/2 - pi/4)
B) J_v(x) approx sqrt(2/(pi*x)) * sin(x - v*pi/2 - pi/4)
C) J_v(x) approx 1/x
D) J_v(x) approx 1/sqrt(x)
13. The Hermite polynomials H_n(x) are related to the Gaussian probability distribution function. They are orthogonal with respect to the weight function exp(-x^2) on the interval:
A) [-1, 1]
B) [0, infinity)
C) (-infinity, infinity)
D) (0, 1]
14. Which of the following is a generating function for Legendre polynomials?
A) exp(2xt - t^2) = Sum_{n=0 to infinity} H_n(x) * t^n / n!
B) 1/sqrt(1 - 2xt + t^2) = Sum_{n=0 to infinity} P_n(x) * t^n
C) exp(2xt - t^2) = Sum_{n=0 to infinity} P_n(x) * t^n / n!
D) 1/sqrt(1 - 2xt + t^2) = Sum_{n=0 to infinity} H_n(x) * t^n
15. The Legendre polynomials P_n(x) have roots that are:
A) All real and lie between -1 and 1
B) All real and lie between 0 and 1
C) All complex
D) All real and lie between -infinity and infinity
16. What is the value of the integral Integral from -1 to 1 of P_n(x) dx for n > 0?
A) 0
B) 1
C) 2
D) 2/(2n+1)
17. Bessel functions of order v are solutions to Bessel's differential equation. If v is not an integer, are J_v(x) and J_{-v}(x) linearly independent?
A) Yes, always
B) No, they are always linearly dependent
C) Only if v is irrational
D) Only if v is positive
18. What is the characteristic feature of Bessel functions of the second kind, Y_v(x), as x approaches 0?
A) They remain finite
B) They approach infinity
C) They oscillate
D) They approach zero
19. Hermite polynomials are defined on the interval:
A) [-1, 1]
B) [0, infinity)
C) (-infinity, infinity)
D) (0, infinity)
20. Which recurrence relation is valid for Hermite polynomials?
A) H_{n+1}(x) = 2xH_n(x) - 2nH_{n-1}(x)
B) H_{n+1}(x) = xH_n(x) - nH_{n-1}(x)
C) H_{n+1}(x) = 2xH_n(x) + 2nH_{n-1}(x)
D) H_{n+1}(x) = 2H_n(x) - 2nH_{n-1}(x)
21. The weight function for the orthogonality of Hermite polynomials is:
A) 1
B) exp(x^2)
C) exp(-x^2)
D) x
22. Hermite polynomials satisfy the orthogonality relation:
A) Integral from -infinity to infinity of exp(-x^2) H_m(x)H_n(x) dx = 0 for m != n
B) Integral from -infinity to infinity of exp(-x^2) H_m(x)H_n(x) dx = 1 for m = n
C) Integral from 0 to infinity of exp(-x^2) H_m(x)H_n(x) dx = 0 for m != n
D) Integral from -1 to 1 of exp(-x^2) H_m(x)H_n(x) dx = 0 for m != n
23. What is the value of H_2(x)?
A) 2x
B) 4x^2 - 2
C) 8x^3 - 12x
D) 1
24. What is the value of H_1(x)?
A) 0
B) 1
C) 2x
D) 4x^2 - 2
25. What is the value of H_0(x)?
A) 0
B) 1
C) 2x
D) 4x^2 - 2
26. What is the notation for the Hermite polynomial of degree n?
A) J_n(x)
B) P_n(x)
C) Y_n(x)
D) H_n(x)
27. When n is a non-negative integer, Hermite's equation has a polynomial solution known as the:
A) Bessel polynomial
B) Legendre polynomial
C) Hermite polynomial
D) Laguerre polynomial
28. The parameter 'n' in Hermite's equation represents the:
A) Order of the Hermite polynomial
B) Degree of the Hermite polynomial
C) Index of the Hermite polynomial
D) Rank of the Hermite polynomial
29. What is the general form of Hermite's differential equation?
A) y'' - 2xy' + 2ny = 0
B) y'' + 2xy' - 2ny = 0
C) y'' - 2xy' + ny = 0
D) y'' + 2xy' + 2ny = 0
30. Legendre polynomials are defined on the interval:
A) (-infinity, infinity)
B) [0, infinity)
C) [-1, 1]
D) (0, 1]
31. Which recurrence relation is valid for Legendre polynomials?
A) (n+1)P_{n+1}(x) = (2n+1)xP_n(x) - nP_{n-1}(x)
B) nP_{n+1}(x) = (2n-1)xP_n(x) - (n-1)P_{n-1}(x)
C) (n+1)P_{n+1}(x) = xP_n(x) - P_{n-1}(x)
D) P_{n+1}(x) = xP_n(x) - nP_{n-1}(x)
32. What is the normalization constant for Legendre polynomials such that the integral from -1 to 1 of [P_n(x)]^2 dx = 2/(2n+1)?
A) 1
B) n
C) 2n+1
D) 1/(2n+1)
33. Legendre polynomials satisfy the orthogonality relation:
A) Integral from -1 to 1 of P_m(x)P_n(x) dx = 0 for m != n
B) Integral from 0 to infinity of P_m(x)P_n(x) dx = 0 for m != n
C) Integral from -1 to 1 of P_m(x)P_n(x) dx = 1 for m = n
D) Integral from -1 to 1 of P_m(x)P_n(x) dx = pi for m = n
34. What is the value of P_2(x)?
A) (1/2)(3x^2 - 1)
B) x^2
C) 3x - 1
D) (1/2)(x^2 - 1)
35. What is the value of P_1(x)?
A) 0
B) 1
C) x
D) x^2
36. What is the value of P_0(x)?
A) 0
B) 1
C) x
D) x^2
37. What is the notation for the Legendre polynomial of degree n?
A) J_n(x)
B) Y_n(x)
C) P_n(x)
D) H_n(x)
38. When n is a non-negative integer, Legendre's equation has a polynomial solution called the:
A) Bessel polynomial
B) Hermite polynomial
C) Legendre polynomial
D) Laguerre polynomial
39. The parameter 'n' in Legendre's equation represents the:
A) Order of the Legendre polynomial
B) Degree of the Legendre polynomial
C) Index of the Legendre polynomial
D) Rank of the Legendre polynomial
40. What is the general form of Legendre's differential equation?
A) (1-x^2)y'' - 2xy' + n(n+1)y = 0
B) (1+x^2)y'' + 2xy' + n(n+1)y = 0
C) y'' + xy' + n(n+1)y = 0
D) (1-x^2)y'' - 2xy' - n(n+1)y = 0
41. The modified Bessel equation is given by x^2 y'' + xy' - (x^2 + v^2)y = 0. Its solutions are known as:
A) Bessel functions of the first and second kind
B) Modified Bessel functions of the first and second kind (I_v and K_v)
C) Spherical Bessel functions
D) Hypergeometric functions
42. For integer order n, what is the relationship between J_{-n}(x) and J_n(x)?
A) J_{-n}(x) = J_n(x)
B) J_{-n}(x) = -J_n(x)
C) J_{-n}(x) = (-1)^n J_n(x)
D) J_{-n}(x) = 1/J_n(x)
43. What is the value of Y_0(0)?
A) 0
B) 1
C) Undefined
D) -Infinity
44. What is the value of J_0(0)?
A) 0
B) 1
C) Undefined
D) Infinity
45. What is the recurrence relation for J_v(x) in terms of J_{v-1}(x) and J_{v+1}(x)?
A) J_v'(x) = (v/x)J_v(x) - J_{v+1}(x)
B) J_v'(x) = J_{v-1}(x) - (v/x)J_v(x)
C) J_v'(x) = (1/2) * [J_{v-1}(x) - J_{v+1}(x)]
D) J_v'(x) = J_{v+1}(x) - J_{v-1}(x)
46. Which Bessel function, Y_v(x), is singular at x = 0 for any v?
A) Bessel function of the first kind
B) Bessel function of the second kind
C) Modified Bessel function
D) Spherical Bessel function
47. Which Bessel function, J_v(x), is finite at x = 0 for v >= 0?
A) Bessel function of the first kind
B) Bessel function of the second kind
C) Modified Bessel function
D) Spherical Bessel function
48. What are the two linearly independent solutions to Bessel's equation called?
A) Legendre functions of the first and second kind
B) Bessel functions of the first and second kind
C) Hermite functions of the first and second kind
D) Laguerre functions of the first and second kind
49. The parameter 'v' in Bessel's equation is known as the:
A) Order of the Bessel function
B) Degree of the Bessel function
C) Index of the Bessel function
D) Rank of the Bessel function
50. What is the general form of Bessel's differential equation?
A) x^2 y'' + xy' + (x^2 - v^2)y = 0
B) x y'' + y' + (x^2 - v^2)y = 0
C) x^2 y'' + x y' + (x - v^2)y = 0
D) y'' + xy' + (x^2 - v^2)y = 0