5. For any real number L > 0, consider the set of functions fx(x) = cos...
(6) (This question does not relate to the above conditions.) Prove that the following system of trigonometric functions is an orthonormal system of L?(-7,7): cos no, sin ne 27 n=1,2,.. Moreover, set f(0) = 62. Write the Fourier expansion off with respect to the system of trigonometric functions in L'(-, 7). Problem 2. We define k00 Example. Let N be a null set. If u(x) = v(x) for x® N, then u(x) = v(x) a.e. Similarly, if lim uk(x) =...
6. a) For a thin conducting rod of length L = π, the temperature U(x, t) at a point 0 Sx S L at timet>0 is determined by the differential equation U, Uxx with boundary data U(x, 0) fx) and U(0,) UL, t)- 0 for all0. Show that for any positive integer k, the function U(x, t)- exp (-ak21) sin kx is a solution. It follows that Σ exp (-ak2 t) Bk sin kx is the general solution where Σ...
Denote the Fourier series of fr-fx, 1<x< 0 f(x) = { 0, 0SX S1 by F(x). Show that E F(x) = - -_ 2500 cos (2mi) + 2m=0 (2m+1) + 500 + 2n=1 + in sin(nx).
Mark which statements below are true, using the following: Consider the diffusion problem au Ou u(0, t) = 0, u(L, t) = 50 u(x,0-fx where FER is a constant, forcing term. Any attempt to solve this using separation of variables fails. This is because the PDE is not homogeneous. A more fruitful approach arises from splitting the solution into the sum of two parts, taking into account that all change eventually dies out. That is there is a transient part...
& The taylor series generated by fx)= et at a 9 is: B) ¿ (xaq) +! ni e (x-ght D o é (x-gin 1-0 (D+1)1 no (n+ ! I cos(x²) dx with an error less than o.ool is about: a) 0.9 6) 0.9046 c) Nore of the above ... 1492 3) The sum of the n n series 1 + 1 + 1 + 1 2 + I c) è se a) b) The sun of the series 1:1 +...
Consider the series following series of functions ' sin(nx) 3 n-1 a) Show that the series is absolutely and uniformly convergent on the real axis. Let f be its summation function n sin(nx) b) Show that f E C(R) and that 1 cos(nx) f'(x)= 2-1 c) Show that 「 f#072821) f(x)dx = k=0 Consider the series following series of functions ' sin(nx) 3 n-1 a) Show that the series is absolutely and uniformly convergent on the real axis. Let f...
(1 point) Solve the wave equation with fixed endpoints and the given initial displacement and velocity. a2 ,0<x<L, t > 0 a(0. t) = 0, u(L, t) = 0, t > 0 Ou Ot ηπα t) + B,, sin (m Now we can solve the PDE using the series solution u(r,t)-> An C computed many times: An example: t) ) sin (-1 ). The coefficients .An and i, are Fourier coefficients we have , cos n-1 sin(n pix/ L) dr...
Definition. Let fi, f2.83.... be a sequence of functions defined on an interval I. The series fn(x) is said to have property 6 on I if there erists a convergent series of positive constants, Mn, satisfying \fu(x) S M for all values of n and for every or in the interval I. n=1 Theorem. If the series (1) has property C on the interval (a, b), and if the terms f(x) are continuous functions on (a, b), then nel 1...
Find the temperature function u(x,t)u(x,t) (where xx is the position along the rod in cm and tt is the time) of a 1818 cm rod with conducting constant 0.10.1 whose endpoint are insulated such that no heat is lost, and whose initial temperature distribution is given by: u(x,0)={5 if 6≤x≤12 {0 otherwise To start, we have L=18 0.1 Because the rods are insulated, we will use the cosine Fourier expansion. 22 Ac + =1 A cos(" )e| A cos( u(x,...
(5) Let W denote the set of smooth functions f(2) in CⓇ such that f'(x) = -f(L). That is, W= {f() in C | F"(x) = -f(x)} In the previous worksheet, we showed that: • W is a subspace of Cº. . For all a and b, a sin(2) + b cos(x) is in W. (a) Show that (sin(x), cos(x)} are linearly independent. Hint: Set an arbitrary linear combination equal to 0, and show the coefficients must be 0. (b)...