Consider the following integrals. Label each as P, C, D, according as the integral is proper, improper but convergent, or improper and divergent.

1. $\int_{4}^{9}\ln(x-4)\,dx$
2. $\int_{-\infty}^{\infty}\frac{x}{x^2+6}\,dx$
3. $\int_{7}^{\infty}\frac{1}{\sqrt{t^2-49}}\,dt$
4. $\int_{1}^{\infty}s e^{7 s^2}\,ds$
5. $\int_{-\infty}^{\infty}\sin(7 x)\,dx$
6. $\int_{0}^{9}\frac{1}{\sqrt[3]{x-4}}\,dx$
7. $\int_{-\pi/4}^{9\pi/2}\tan^2(7 x)\,dx$
8. $\int_{-6\pi}^{42\pi}\sin(x)\tan^{-1}(x)\,dx$