Question

How do you use a calculator to evaluate ${\sin ^{ - 1}}\left( {0.99} \right)$ in both radians and degrees?

Answer 1

The trigonometric functions are used to find the missing angles for any right-angled triangle. We can use Texas instruments calculators for finding the values for inverse trigonometric functions. Now, in this question we will learn how to use such calculators for radian as well as degrees.

Complete step by step solution:
We have to find the value of ${\sin ^{ - 1}}\left( {0.99} \right)$ using a calculator for both radians and degrees.
Now, we are using the Texas instruments graphing calculators commonly known as TI calculators. For using such calculators firstly press the MODE button and then after pressing it select RADIAN option which will appear by pressing it twice and then press ENTER to fix the radian option.
Now, enter the expression by pressing the SHIFT button and select “sin” on the calculator. Then on the screen we will see the ${\sin ^{ - 1}}$ Now enter the term whose value we want to calculate. Now ${\sin ^{ - 1}}\left( {0.99} \right)$ will appear. After pressing ENTER, we will get our value for radian sine function.
The value appeared is $1.429256$
Now, CLEAR the screen of the calculator to find the value of sine in degrees:
Step $1$: press MODE button.
Step $2$: choose RADIAN option.
Step $3$: press shift and press ${\sin ^{ - 1}}$ on the calculator
Step $4$: enter the bracket term whose value we want to find. At last press ENTER, we will get our value for degrees for sine function.
The value appeared is $81.89038554$

Note: In such questions, students got confused while choosing the options in the MODE options and how to select that option. We may choose the wrong option and the whole question may get wrong. Students always use the calculator in a hurry and make silly mistakes while choosing the sine function or inverse sine function.