hp40g+.book Page 8 Friday, December 9, 2005 1:03 AM

(– X) apply to it. As a result, the entered expression is interpreted, and displayed, as (2 + X)(3 – X).

Select the entire expression

by pressing and evaluate it by pressing . The result is:

–(X2–X–6)

Example2

To enter X2–3X+1, press:

2 – 3 +1

If, instead, you had to enter –x2–3X+1, you would need to press:

(–) 2 – 3 +1

Note that you press twice to ensure that the exponent applies to –X and not just to X.

Example 3

Suppose you want to enter:

1

1

1

1

--

+ --

+ --

+ --

2

3

4

5

Each fraction can be viewed as a separate branch on the equation tree. In the Equation Writer type the first branch:

1 ÷ 2

and then select this branch by pressing .

Now type + and enter the second branch:

1 ÷ 3

Select the second branch by pressing .

Now type + and enter the third branch:

1 ÷ 4

Likewise, select the third branch by pressing , type + and then the fourth branch:

1 ÷ 5

15-8

 

 

Equation Writer