184 Section 13: Finding the Roots of an Equation
You have now found the two roots of
f(x)
= 0. Note that this quadratic equation
could
have been solved algebraically – and
you would have obtained the same roots
that you found using
_
.
G
G
r
The convenience and power of the
_
key become more apparent
when you solve an equation for a root that cannot be determined
algebraically.
Example:
Champion ridget hurler Chuck
Fahr throws a ridget with an upward
velocity of 50 meters/second. If the height
of the ridget is expressed as
h
= 5000(1 – e
–t/20
) – 200
t,
how long does it take for it to reach the
ground again? In this equation,
h
is the
height in meters and
t
is the time in seconds.
Solution:
The desired solution is the positive value of
t
at which
h
= 0.
Use the following subroutine to calculate the height.
Keystrokes
Display
|
¥
000–
´
bA
001–42,21,11
Begin with label.
2
002– 2
Subroutine assumes
t
is
loaded in X-and Y-registers.
0
003– 0
÷
004– 10
Summary of Contents for HP-15C
Page 1: ...HP 15C Owner s Handbook HP Part Number 00015 90001 Edition 2 4 Sep 2011 ...
Page 17: ...Part l HP 15C Fundamentals ...
Page 64: ......
Page 65: ...Part ll HP 15C Programming ...
Page 118: ...118 ...
