In: Advanced Math
For the following exercises, match each trigonometric function with one of the graphs in Figure 18.
f(x) = sec x
Consider the following trigonometric function:
f(x) = secx
The above equation is reciprocal of cosine function, so the function can be rewritten as,
f(x) = 1/cosx
To acknowledge the graph among the provided graphs in textbook, first sketch the graph of above function,
Put x = 0 in the above function,
f(0) = 1/cox(0)
= 1/1
= 1
Put x = π/4 in the above function,
f(π/4) = 1/cos(π/4)
= 1/(1/√2)
= √2
Put x = π/3 in the above function,
f(π/3) = 1/cos(π/3)
= 1/(1/2)
= 2
Put x = 2π/3 in the above function,
f(2π/3) = 1/cos(2π/3)
= 1/(-1/2)
= -2
Put x = π in the above function,
f(π) = 1/cosπ
= 1/(-1)
= -1
Now draw the table for the above values of function,
x | 0 | π/4 | π/3 | 2π/3 | π |
f(x) | 1 | √2 | 2 | -2 | -1 |
Now plot the graph with the table,
Hence it is cleared that the graph IV provided in the textbook is the graph of the function
f(x) = secx.
Hence it is cleared that the graph IV provided in the textbook is the graph of the function
f(x) = secx.