Dawnbridge

TI-84 Plus CE field manual for IB Math

Everyone · 12 of 41

12

Evaluating a stored function

All courses

Store a function in the graph editor, then recall it on the calculation screen to evaluate f(a) at a chosen point.

Goal

Evaluate ​y=ln(x+2)+x2​ at ​x=1.6.

1

Press and type the function on Y1=: .

NORMALFLOATAUTOREALRADIANMP
Plot1Plot2Plot3
\Y1=ln(X+2)+X2
\Y2=
\Y3=
\Y4=
\Y5=
\Y6=
\Y7=
\Y8=
2

Return to the home screen with . Press , move across to Y-VARS with , then choose 1:Function and 1:Y1. The calculator pastes Y1 on the home screen, without an open paren.

3

Open the paren yourself with , type the input with , close the bracket with , and press to evaluate.

NORMALFLOATAUTOREALRADIANMP
Y1​(1.6)
3.840933845
Result

At ​x=1.6, the function value is approximately ​3.84.

Your turn

Work each one on your calculator, then check the answer.

  1. 1

    Evaluate ​f(x)=ln(x+4)−x​ at ​x=1.8.

  2. 2

    Evaluate ​f(x)=ex−x3​ at ​x=2.3.

  3. 3

    Evaluate ​f(x)=e0.5x+x2​ at ​x=2.2.