Chapter 1 - Trigonometric Functions - Section 1.3 Trigonometric Functions - 1.3 Exercises - Page 28: 21

$\sin\theta=\frac{y}{r}=\frac{0}{4}=0$ $\cos\theta=\frac{x}{r}=\frac{-4}{4}=-1$ $\tan\theta=\frac{y}{x}=\frac{0}{-4}=0$ $\csc\theta=\frac{r}{y}=\frac{4}{0}=undefined$ $\sec\theta=\frac{r}{x}=\frac{4}{-4}=-1$ $\cot\theta=\frac{x}{y}=\frac{-4}{0}=undefined$

$x=-4$ $y=0$ $r=\sqrt{(-4)^{2}+(0)^{2}}=\sqrt {0+16}= 4$