HP 15c - Manual (Page 29)

Section 2: Numeric Functions 29
Two-Number Functions
The HP-15C performs two-number math functions using two values entered
sequentially into the display. If you are keying in both numbers, remember
that they must be separated by v or any other function – like |
‘ or ∕ – that terminates digit entry.
For a two-number function, the first value entered is considered the y-value
because it is placed into the Y-register for memory storage. The second
value entered is considered the x-value because it remains in the display,
which is the X-register.
The arithmetic operators, +, -, *, and ÷, are the four basic two-
number functions. Others are given below.
The Power Function
Pressing Y calculates the value of y raised to the x power. The base
number, y, is keyed in before the exponent, x.
To Calculate Keystrokes Display
2
1.4
2 v 1.4 Y
2.6390
2
-1.4 2 v 1.4 “ Y
0.3789
(-2)
3
2 “ v 3 Y
-8.0000
3
2 or 2
1/3 2 v 3 ∕ Y
1.2599
Percentages
The percentage functions, k and ∆, preserve the value of the original
base number along with the result of the percentage calculation. As shown
in the example below, this allows you to carry out subsequent calculations
using the base number and the result without re-entering the base number.
Percent. The k function calculates the specified percentage of a base
number.