1.4 Uniform Convergence

1.4 Uniform Convergence

  • The semicircle is centered at the origin.
  • The convergence is treated at individual points of an interval.
    • Uniform convergence in an interval is a stronger kind of convergence.

  • There are two important facts.
    • If a series converges uniformly in a period interval, it must converge to a continuous function.

  • It is uniform.
  • Figure 10 shows graphs of a "sawtooth" function and partial sums of its Fourier series.
    • The convergence is uniform.
  • One way to prove uniform convergence is to look at the coef ficients.

  • If f is periodic and continuous and has a sectionally continuousderivative, the Fourier series corresponding to f converges uniformly to the real axis.

  • There is no such difficulty with the even periodic extension.

  • Determine if the following functions converge uniformly or not.

  • The convergence is not different.
  • Determine if the following functions converge uniformly.

  • If you want to decide whether the convergence of the associate Fourier series is uniform, use Theorem 1.