Problem 14
Show that the indicial equation of the given differential equation has distinct roots that do not differ by an integer and find two linearly independent Frobenius series solutions on \((0, \infty)\). $$3 x^{2} y^{\prime \prime}-x(x+8) y^{\prime}+6 y=0$$
Problem 15
Show that the indicial equation of the given differential equation has distinct roots that do not differ by an integer and find two linearly independent Frobenius series solutions on \((0, \infty)\). $$2 x^{2} y^{\prime \prime}-x(1+2 x) y^{\prime}+2(4 x-1) y=0$$
Problem 16
Consider the Chebyshev equation $$\left(1-x^{2}\right) y^{\prime \prime}-x y^{\prime}+a^{2} y=0, \quad (11.7.10)$$ where \(a\) is a constant. (a) Show that if \(a=N,\) a nonnegative integer, then Equation (11.7.10) has a polynomial solution of degree \(N .\) When suitably normalized, these polynomials are called the Chebyshev polynomials and are denoted by \(T_{N}(x).\) (b) Use Equation (11.7.10) to show that \(T_{N}(x)\) satisfies $$\left[\sqrt{1-x^{2}} T_{N}^{\prime}\right]^{\prime}+\frac{N}{\sqrt{1-x^{2}}} T_{N}=0.$$ (c) Use the result from (b) to prove that $$\int_{-1}^{1} \frac{T_{N}(x) T_{M}(x)}{\sqrt{1-x^{2}}} d x=0, \quad M \neq N.$$
Problem 16
Determine two linearly independent solutions to the given differential equation on \((0, \infty)\) $$4 x^{2} y^{\prime \prime}+(1-4 x) y=0$$
Problem 17
Show that the indicial equation of the given differential equation has distinct roots that do not differ by an integer and find two linearly independent Frobenius series solutions on \((0, \infty)\). $$3 x^{2} y^{\prime \prime}+x(7+3 x) y^{\prime}+(1+6 x) y=0$$
Problem 18
Determine the Fourier-Bessel expansion in the functions \(J_{0}\left(\lambda_{k} x\right)\) of \(f(x)=x^{2}\) on the interval (0,1) [Here the \(\left.\lambda_{k} \text { denote the positive zeros of } J_{0}(x) .\right]\)
Problem 20
Show that the change of variables \(y=x^{1 / 2} u\) transforms the differential equation $$y^{\prime \prime}+\left(1-\frac{3}{4 x^{2}}\right) y=0$$ into the Bessel equation $$x^{2} u^{\prime \prime}+x u^{\prime}+\left(x^{2}-1\right) u=0$$ and thereby write the general solution to the given differential equation.