Let's turn to the functions and see how they work with this inverse key.
Notice that the numerator and denominator of the cosecant, H/O, are the reverse of the sine, O/H. They have an inverse relationship. In fact, all the functions on the right are inverse to the functions on the left, and vice versa.
For example: With the 3-4-5 right triangle, the Sin = 3/5 and the Csc = 5/3. 3/5 = 0.6 and 5/3 = 1.67
This chart shows these inverse relationships.
To determine a function using the inverse key:
- First: Determine the function which is inverse to the function you want.
- Second: Do your calculations based on that function.
- Third: Push the inverse key 1/x.
For example, to find the cosecant of an angle:
For example: The cosecant of 24° is found in this manner.
The cosecant of 24° is 2.4589.
Using the Inverse Key with Functions: Practice
Find the indicated function for each angle below. Round off to 4 decimal places.
Remember: Use the calculator key that is the inverse of these functions first, then the 1/x key.
(1) csc 40° (5) cot 60°
(2) sec 45° (6) csc 24°
(3) cot 34° (7) sec 65°
(4) sec 12° (8) cot 1°