TI-84 Guides
How to do it on a TI-84.
Step-by-step keystrokes for Algebra II, Pre-Calculus, and Geometry. Every guide plays its keys on a free online TI-84 so you can watch it happen.
Essentials.
How to Type a Negative Number on a TI-84
The (−) key makes a number negative. The − key subtracts. Mixing them up is the #1 cause of ERR:SYNTAX.
How to Get a Fraction Answer on a TI-84
Add ►Frac to the end of any calculation to see the answer as a fraction.
How to Use Ans (Last Answer) on a TI-84
ANS holds the previous result, so you can keep working without retyping decimals.
How to Recall and Edit Your Last Entry on a TI-84
2nd ENTER brings back what you just typed so you can edit it instead of starting over. Press it again to go further back.
How to Round Answers to 2 Decimal Places on a TI-84
Set Fix 2 in MODE. Change it back to FLOAT the same way.
How to Store a Value in a Variable on a TI-84
STO→ saves a number in a variable. ALPHA gets the green letters.
How to Enter Scientific Notation on a TI-84
2nd , (EE) means “times 10 to the”. Type 3.2 EE 5 for 3.2 × 10⁵.
How to Reset a TI-84 Calculator
Clears every setting, function, and list. Good before a test or when a student’s calculator is acting strange.
Algebra II & Pre-Calc.
How to Graph a Function on a TI-84
Enter the function in Y=, then use ZStandard for the −10 to 10 window.
How to Find Zeros (x-Intercepts) on a TI-84
At each prompt you can type a number instead of arrowing. Pick bounds on either side of one zero.
How to Find a Maximum or Minimum on a TI-84
Same steps as zero: CALC 3 is minimum, CALC 4 is maximum.
How to Find the Intersection of Two Graphs on a TI-84
Graph each side of the equation. The x-value where they cross is the solution. Here: 2x + 1 = −x + 7.
How to Evaluate a Function on the TI-84 Graph
CALC 1 (value) jumps the cursor to any x in the window. ▲▼ switch between functions.
How to Evaluate f(3) on the TI-84 Home Screen
VARS ▶ 1 1 pastes Y1. Then Y1(3) works just like f(3).
How to Make a Table of Values on a TI-84
TBLSET picks the starting x and the step. TABLE shows x and every Y.
How to Set the Graph Window on a TI-84
Type each value and press ENTER to move down. Xscl and Yscl set the tick marks.
How to Trace a Graph on a TI-84
TRACE puts the cursor on the curve. ◀▶ move along it. Typing a number jumps to that x.
How to Turn On r and r² (Diagnostics) on a TI-84
Do this once so regressions show the correlation coefficient.
How to Do Linear Regression on a TI-84
Enter data in STAT 1 (Edit): x in L1, y in L2. The wizard can also paste the equation into Y1.
How to Do Exponential Regression on a TI-84
Same wizard as LinReg. ExpReg is STAT ▶ 0 and fits y = a·bˣ.
How to Solve a System of Equations with Matrices on a TI-84
x + y + z = 6, 2x − y + z = 3, x + 2y − z = 2. Enter the augmented matrix, then rref( gives the solution in the last column.
How to Do a Log with Any Base on a TI-84
MATH A is logBASE(. Here: log₂(8).
How to Use e and ln on a TI-84
2nd LN is eˣ. LN undoes it: ln(e²) = 2.
How to Do Cube Roots and nth Roots on a TI-84
MATH 4 is ³√(. For any root, type the index first, then MATH 5 (ˣ√).
How to Do Absolute Value on a TI-84
MATH ▶ (NUM), 1 is abs(. Graph it the same way in Y=.
How to Do Combinations (nCr) on a TI-84
MATH ◀◀ reaches the PROB menu. 3 is nCr, 2 is nPr, 4 is !.
How to Graph Trig Functions on a TI-84
ZOOM 7 sets a window marked in π/2 steps. Use RADIAN mode for x in radians.
Geometry.
How to Put a TI-84 in Degree Mode
Geometry angles are in degrees. The top bar shows DEGREE when you are set.
How to Find a Missing Side with Sin, Cos, and Tan on a TI-84
Hypotenuse 12, angle 35°. Opposite side = 12 sin(35°).
How to Find an Angle with Inverse Trig on a TI-84
Opposite 7, hypotenuse 10. The angle is sin⁻¹(7/10). 2nd SIN is sin⁻¹.
How to Use the Pythagorean Theorem on a TI-84
Legs 5 and 12. Hypotenuse = √(5² + 12²). 2nd x² is √(.
How to Use the Distance Formula on a TI-84
From (1, 2) to (4, 6): √((4 − 1)² + (6 − 2)²).
How to Use π and Find the Area of a Circle on a TI-84
Radius 6. 2nd ^ is π. Leave the answer in the calculator instead of rounding π to 3.14.
How to Find Sector Area on a TI-84
A 60° sector of a circle with radius 5: (60/360)·π·5².
How to Use the Law of Cosines on a TI-84
Sides 7, 8, 9. The angle across from 9 is cos⁻¹((7² + 8² − 9²) ÷ (2·7·8)).
How to Use the Law of Sines on a TI-84
a / sin(40°) = 10 / sin(65°), so a = 10 sin(40°) ÷ sin(65°).
How to Round to the Nearest Tenth on a TI-84
MATH ▶ (NUM), 2 is round(value, decimal places).
How to Find the Volume of a Sphere on a TI-84
Radius 3: (4/3)πr³. MATH 3 is the ³ (cubed) key.