MA 3972-MA-Book May 8, 2018 13:46
62 STEP 4. Review the Knowledge You Need to Score High
[−10, 10] by [10, 10]
Figure 5.3-6
(b) By inspection, the graph of f(x)=x^3 − 2 x+1 in Figure 5.3-7 fails the horizontal line
test. Thus,f(x) has no inverse function.
[−8, 8] by [−4, 3]
Figure 5.3-7
Example 3
Find the inverse function off(x)=
√
2 x− 1 .(See Figure 5.3-8.)
y = x
f
f−^1
y
0 x
0.5
0.5
Figure 5.3-8
- Sincef(x) is a strictly increasing function, the inverse function exists.
- Lety= f(x).Thus,y=
√
2 x−1.
- Interchangexandy.You havex=
√
2 y−1.