TI-84 Plus CE field manual for IB Math
28
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
Open the derivative template: press , then . This inserts d□d(□)∣∣□=□ with the cursor in the variable box.
2
Type for the variable, move into the expression box and type , 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.