Exercise 35 Page 475

We can use a calculator to evaluate a reciprocal trigonometric ratio using the $\boxed{\text{SIN}},$ $\boxed{\text{COS}},$ and $\boxed{\text{TAN}}$ buttons. We first need to rewrite the function using its reciprocal counterpart.

$$\begin{array}{c}\text{csc}\left(\frac{10\pi }{11}\right)=\frac{1}{\text{sin}\left(\frac{10\pi }{11}\right)}\end{array}$$

Be sure to always check that your calculator is in the correct mode. In this case, we need radians.