Entering Expressions and Instructions

TI-84 Plus Silver Edition Expressions, Menus, and Graphing

What is an Expression?

An expression is a group of numbers, variables, or functions and their arguments, or a combination of these elements. An expression evaluates to a single answer. For example,( 13 )2 is an expression. On the TI-84 Plus Silver Edition, you enter an expression in the same order as you would write it on paper. You can enter an

expression on the home screen to calculate an answer.

Entering an Expression

To create an expression, you enter numbers, variables, and functions from the keyboard and menus on your TI-84 Plus Silver Edition. An expression is completed when you press Õ, regardless of the cursor location. The entire expression is evaluated according to Equation Operating System (EOS™) rules (see General Math page), and the answer is displayed. When an entry is

executed on the home screen, the answer is displayed on the right side of the next line.

The mode settings control the way the TI-84 Plus Silver Edition interprets expressions and displays answers. If an answer, such as a list or matrix, is too long to display entirely on one line, an

ellipsis (...) is displayed to the right or left. Press ~or to display the rest of the answer.

To display the MATH menu, pressç

MATH NUM CPX PRB

1:	Frac		Displays answer as a fraction
2:	Dec		Displays answer as a decimal
3: 3			Calculates cube
4: 3√		(	Calculates cube root

5: x√			Calculates xth root

6: fMin(			Finds minimum of a function
7: fMax(			Finds maximum of a function
8: nDeriv(			Computes numeric derivative
9: fnInt(			Computes integral of a function
0: Solver...			Displays equation solver

To display the MATH NUM menu, pressç~

MATH NUM CPX PRB

1:	abs(	Computes absolute value
2: round(		Rounds value to specified decimal place
3: iPart(		Calculates integer part
4: fPart(		Calculates fractional part
5: int(		Finds greatest integer less than or equal to number
6: min(		Finds minimum value
7: max(		Finds maximum value
8: lcm(		Calculates least common multiple
9: gcd(		Calculates greatest common divisor

To display the MATH PRB menu, pressç

MATH NUM CPX PRB

1:	rand	Generates random number between 0 and 1
2: nPr		Computes number of permutations
3: nCr		Computes number of combinations
4: !		Calculates factorial
5: randInt(		Generates random integer in specified range
6: randNorm(		Generates random # from Normal distribution
7: randBin(		Generates random # from Binomial distribution

Defining or Editing a Function for Graphing

To Define or Edit a Function

1Press oto display the Y= editor.

2Press Üto move the cursor to the function you want to define or edit. To erase a function, pressë.

3Enter or edit an expression to define the function.

Displaying a New Graph

To display a graph of the selected function, press s. TRACE, ZOOM, and CALC operations display the graph automatically. As the graph is plotted, the busy indicator is on, and the X and Y values are updated.

Free-Moving Cursor

When you first display the graph, no cursor is visible. You must press ~}or Üfor the cursor to move from the center of the viewing window. Continue pressing~}or Üto move the cursor around.

Tracing a Function

Use the TRACE operation to move the cursor from one plotted point to the next along a function. To begin, pressr. The TRACE cursor is on the first selected function in the Y= editor, centered horizontally on the screen. The cursor coordinates are displayed at the bottom of the screen if CoordOn format is selected. The Y= expression is displayed in the top left corner of the screen ifExprOn format is selected.

Moving the TRACE Cursor
To move the TRACE cursor	Do this:

To the previous or next plotted point	Press or ~

Five plotted points on a function	Press y or y ~
(Xres affects this)

To any valid X value on a function	Enter a value & pressÕ

From one function to another	Press }or Ü

To alter the viewing area of the graph, pressq

ZOOM MEMORY

1: ZBox		Draws a box to define the viewing window
2: Zoom In		Magnifies the graph around the cursor
3: Zoom Out		Views more of a graph around the cursor
4: ZDecimal		Sets X and Y to 0.1
5: ZSquare		Sets equal-size pixels on the X and Y axes
6: ZStandard		Sets the standard window variables
7: ZTrig		Sets the built-in trig window variables
8: ZInteger		Sets integer values on the X and Y axes
9: ZoomStat		Sets the values for current stat plots
0: ZoomFit		Fits Ymin and Ymax between Xmin and Xmax
To display the CALCULATE menu, pressy/

1:	CALCULATE	Calculates a function Y value for a given X
	value
2:	zero	Finds a zero (x-intercept) of a function
3: minimum		Finds a minimum of a function
4: maximum		Finds a maximum of a function
5: intersect		Finds an intersection of two functions
6: dy/dx		Finds a numeric derivative of a function
7: ∫f(x)dx		Finds a numeric integral of a function

To return to the Home Screen from any other screen, pressy5.

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TI-84 Plus Silver Edition Expressions, Menus, and Graphing