Brand: | CASIO |
Model: | fx-19 |
Type: | Scientific calculator |
Picture: | |
Batteries: | AA x 4 |
Lifetime: |
Introduced: ca. 1976 Terminated: unknown |
Notes: |
A CASIO scientific calculator with a fluorescent display, a
slider to switch between modes, and capable of calculating with fractions
and statistical operations.
Quite similar to the CASIO fx-29. As far as I can tell the main difference is the layout, the casing and the number of batteries. The workings of the "xy"-key might be puzzling to users of this calculator. When you enter a (positive) number and press the "xy"-key an intermediate result is shown, being the natural log "ln" of the number entered. To obtain its power enter the value for y and press the "="-key. My guess is that this calculator uses this formula:
xy = e(y · ln x)
This works nicely for positive values of x but will result in an
error when x is zero or less. Not a big problem because powers of negavive
numbers behave counter intuitive anyway (producing non-complex results
only for integer values of y or fractional values of y with an odd
denominator).
This calculator has separate keys for the exponent and the constant π instead of the combined key of most other scientific calculators by CASIO (where the "EXP"-key will enable you to enter the numbers exponent when you first enter digits, and will otherwise enter the constant π). There’s also no "INV"-key, only an "arc"-key for the inverse trigonometric functions. Statistical functions are available when the mode selector slider is all the way to the right. |
©2024 Ernst Mulder