Sharp EL9900 manual Slope and Intercept of Linear Equations

EL-9900 Graphing Calculator

Slope and Intercept of Linear Equations

A linear equation of y in terms of x can be expressed by the slope-intercept form y = mx+b, where m is the slope and b is the y - intercept. We call this equation a linear equation since its graph is a straight line. Equations where the exponents on the x and y are 1 (implied) are considered linear equations. In graphing linear equations on the calculator, we will let the x variable be represented by the horizontal axis and let y be represented by the vertical axis.

Example

Draw graphs of two equations by changing the slope or the y- intercept.

1. Graph the equations y = x and y = 2x.

2. Graph the equations y = x and y = 12 x.

3. Graph the equations y = x and y = - x.

4. Graph the equations y = x and y = x + 2.

	Before	There may be differences in the results of calculations and graph plotting depending on the setting.
Starting		Return all settings to the default value and delete all data.
	Step & Key Operation		Display	Notes

1-1Enter the equation y = x for Y1 and y = 2x for Y2.

Y=

X//T/n

ENTER 2

X//T/n

1-2View both graphs.

GRAPH

The equation Y1 = x is dis- played first, followed by the equation Y2 = 2x. Notice how Y2 becomes steeper or climbs faster. Increase the size of the slope (m>1) to make the line steeper.

2-1	Enter the equation y =						1	x for Y2.
							2
		Y=			CL
		1	a/b	2		X/ /T/n
2-2	View both graphs.
		GRAPH

Notice how Y2 becomes less steep or climbs slower. De- crease the size of the slope (0<m<1) to make the line less steep.

3-1