HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010

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TRUNCATE(<num>)

This function operates similarly to the

ROUND function, but simply drops

the extra digits instead of rounding up or down. It is somewhat similar

in effect to the

FLOOR function but the TRUNCATE function will work to

any number of decimal places or significant figures instead of always

dropping to the nearest lower integer value.

Eg.

TRUNCATE(3405.6375,-6) = 3405.63

TRUNCATE(32.889,1) = 32.8

See also:

INT, FLOOR, CEILING, ROUND,FRAC

XPON(<num>)

This function returns the exponent (indicial part) when transformed into

scientific notation of the number you feed it. It would be used with the

XPON function, which returns the power part of the number when in

scientific notation.

Eg. Change

487 23 into scientific notation to get 4 8723 ×10

MANT(487.23) = 4.8723

XPON(487.23) = 2

Change

0 0005087 into scientific notation to get 5 087 ×10

−

MANT(0.0005087) = 5.087

XPON(0.0005087) = -4

This function could be of use to you if you are just learning scientific notation, but is of more use to people

writing programs. A normal user would just look at the number and see the answer, but a programmer would

not know in advance what number was going to be used and so might use

MANT and XPON to find the size

of a number that the user has just entered.