HP HP-21 - Raising Numbers to Powers

50 Function Keys
Raising Numbers to Powers
E permits you to raise a positive number (either an
integer or a decimal) to any power. For example, calculate
29 2 X2X2X2X2X2X2X2XxX2).
Press Display
2 9] 512.00
Now find 8!-2567,
Press Display
8 ENED 8.00
1.2567 I )
In conjunction with ¥ provides a simple way to
extract roots. For e{(ample, find the cube root of 5. (This may
also be written as 573):
Press Display
s
3 Reciprocal of 3.
] 1.71 Cube root of 5.
Example 1: A particularly hopped-up Vincent Black Shadow
motorcycle rockets along a straight line according to the
equation
Distance = %5 (t® + 8t).
Determine the Shadow’s velocity (V) and acceleration (A) after
two seconds (t = 2), according to the formulas:
V (ft./sec.) = 3t + 4 =(3 x 25)+ 4
A (ft./sec.?) = 15t = 15 x 2¢
Solution:
Press Display
2 5 58
3
4[+] Ft/sec. The Shadow’s
velocity.
» D ¢+
15 [x] Ft/sec.? The Shadow’s
acceleration.