Sharp EL-9400, EL-9600c EL-9650/9600c/9450/9400 Graphing Calculator, Evaluate, Is x /y = x/y?

EL-9650/9600c/9450/9400 Graphing Calculator

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(When using EL-9650/9600c)	(When using EL-9650/9600c)
*Use either pen touch or cursor to operate.

2-2Is x + y = x +y? Think about this problem according to the cases

when x or y are positive or negative.

If x ≥ 0 and y ≥ 0 [e.g.; (x, y) = (2,7)]

If x ≤ 0 and y ≥ 0 [e.g.; (x, y) = (-2, 7)]

If x ≥ 0 and y ≤ 0 [e.g.; (x, y) = (2, -7)]

If x ≤ 0 and y ≤ 0 [e.g.; (x, y) = (-2, -7)]

x +y = 2 + 7 = 9

x+y = 2 + 7 = 9

x + y = x + y.

x +y = -2 + 7 = 5

x+y = -2 + 7 = 9

x + y ≠ x + y.

x +y = 2-7 = 5

x+y = 2 + -7 = 9

x + y ≠ x + y.

x +y = -2-7 = 9

x+y = -2 + -7 = 9

x + y = x + y.

Therefore x +y=x+ywhen x ≥ 0 and y ≥ 0, and when x ≤ 0 and y ≤ 0.

3-1	Evaluate					6-9			. Evaluate						6-9			.
						1+3								1+3
		CL		MATH			1	*		a/b		6			—		9
			*	1			+		3		ENTER
		MATH		1	*	6			—		9					*	a/b
		MATH		1 *		1		+			3		ENTER
3-2
	Is x /y = x/y?

Think about this problem according to the cases when x or y are positive or negative.

If x ≥ 0 and y ≥ 0 [e.g.; (x, y) = (2,7)]

If x ≤ 0 and y ≥ 0 [e.g.; (x, y) = (-2, 7)]

If x ≥ 0 and y ≤ 0 [e.g.; (x, y) = (2, -7)]

If x ≤ 0 and y ≤ 0 [e.g.; (x, y) = (-2, -7)]

6-9	6-9
1+3	= 0.75 , 1+3	= 0 .75

➞6-9 = 6-9

1+3 1+3

x /y = 2/7 = 2/7

x/y = 2 /7 = 2/7

x /y = x / y

x /y = (-2)/7 = 2/7

x/y = -2 /7 = 2/7

x /y = x / y

x /y = 2/(-7) = 2/7

x/y = 2 /-7 = 2/7

x /y = x / y

x /y = (-2)/-7 = 2/7

x/y = -2 /-7 = 2/7

x /y = x / y

The statement is true for all y ≠ 0.

The EL-9650/9600c/9450/9400 shows absolute values with , just as written on paper, by using the Equation editor. The nature of arithmetic of the absolute value can be learned through arithmetical operations of absolute value functions.

8-5