Graphs of derivatives, Continued) – Sharp EL-9900 User Manual
Page 84
9
Advanced Keyboard/CALCULUS USING THE SHARP EL-9900
Copyright © 2002, Sharp Electronics Corporation. Permission is granted to photocopy for educational use only.
9. Graph the second derivative by pressing Y= ENTER ENTER , and input
d/dx (Y2) in the Y3 location with the keystrokes MATH A (CALC)
0 5
(d/dx
(
) 2ndF VARS ENTER A (XY) 2 (Y2) and press )
ENTER .
10. Press GRAPH to obtain the graphs of f(x), f ’(x), and f ’’(x). Where is f ’’(x).
zero? After pressing TRACE
▼ ▼ to place the tracer on the second
derivative, press 2ndF CALC 5 (X_Incpt) to find that f ’’(x) = 0 at
X= 1.167.
11. Find the y-value of this point of inflection by pressing
▲ ▲ to move the
cursor to the original function. Press 2ndF CALC 1 (Value) and enter
1.167 and press ENTER .
12. The connections we have discovered between the graphs of f(x), f ’(x), and
f ’’(x) are summarized in the tables below.
GRAPHS OF DERIVATIVES
(continued)
x < -2.4427
-2.4427 < x < 1.1656
1.1656 < x < 4.776
x > 4.776
x – value
x = -2.4427
x = 1.16567
x = 4.776