Chapter 4.3, Problem 36E

(a)

To determine

The value of $\sec 1.54$ using a calculator and round it to four decimal places.

Answer to Problem 36E

The value of $\sec 1.54$ is $32.4765$ .

Explanation of Solution

Given:

The trigonometric identity is $\sec 1.54$ .

Calculation:

The value of $\sec 1.54$ can be calculated by graphical calculator.

Steps to calculate the values using a graphical calculator is as follows.

1. Start calculator and press the “Y” button to enter the function screen.
2. Type the trigonometric function to calculate its value.
3. Press “Enter” to show the result.

So, the value of $\sec 1.54$ using the calculator is,

  $\sec 1.54=32.4765382934$

Round off the answer to four decimal places gives $32.4765$ .

Therefore, $\sec 1.54=32.4765$ .

(b)

To determine

The value of $\cos 1.25$ using a calculator and round it to four decimal places.

Answer to Problem 36E

The value of $\cos 1.25$ is $0.3153$ .

Explanation of Solution

Given:

The trigonometric identity is $\cos 1.25$ .

Calculation:

The value of $\cos 1.25$ can be calculated by graphical calculator.

Steps to calculate the values using a graphical calculator is as follows.

4. Start calculator and press the “Y” button to enter the function screen.
5. Type the trigonometric function to calculate its value.
6. Press “Enter” to show the result.

So, the value of $\cos 1.25$ using the calculator is,

  $\cos 1.25=0.3153223624$

Round off the answer to four decimal places gives $0.3153$ .

Therefore, $\cos 1.25=0.3153$ .