Casio fx-CG50 field manual for IB Math
27
All coursesEvaluating f′(a) numerically
Use the calculator's derivative template to evaluate f′(a) at a specified point.
Find f′(2.5) for f(x)=xx.
1
From the MAIN MENU open Run-Matrix (icon 1). Check Input/Output is set to Math under (SET UP), then insert the derivative template: press (MATH), then (d/dx).
2
Enter the expression , then move to the evaluation box and type so it reads X=2.5.
3
Press to evaluate.
f′(2.5)≈18.9.
Your turn
Work each one on your calculator, then check the answer.
- 1
Find f′(1.8) for f(x)=x2x.
- 2
Find f′(4) for f(x)=(lnx)x.
- 3
Find f′(3) for f(x)=x1/x.