hp calculators
HP 9s Powers and Roots
.27=*9H\~h
1
)
swer:
(or
U
M.27=*9HN~h
An
6:
Both methods return 0.552528294
Example
of 253 people has the same birthday as you.
Find the probability that at least one
Solution:
The probability that the birthday of at least one of n persons is a particular day is given by:
n
⎟
⎠
⎜
⎝
−
365
1
. In this example n = 253:
⎞
⎛
354
1-M
NB253\
nswer:
364/365
A
that for n
≤
252, the probability is
e probability of at least one of
Example 7:
0.500477154. The probability is greater than 50%. You can easily check
0%, so 253 is the smallest number of persons such that th
smaller than 5
them having the same birthday as you is greater than 50%!
ss
e element for the Mohr circle input (
τ
xy
) is
Solution:
Find the maximum shear stress on an element if the stress in the x –direction (S
x
) is 25,000 psi, the stre
in the y-direction (S
y
) is –5,000 psi and the shear stress on th
4,000 psi.
The maximum shear stress is given by the following formula:
2
2
y
x
S
S
⎞
⎛
−
2
xy
max
τ
+
⎟⎟
⎠
⎜⎜
⎝
=
τ
25A3-5=A3\/2\O+4AO\F
nswer:
A
15,524.1747
psi.
Example 8: Find the geometric mean of the set of numbers { 2, 3.4, 3.41, 7, 11, 23 }
Solution:
For a set of n positive numbers { a
1
, a
2
, ..., a
n
} the geometric mean is defined as
1
n
n
)
a
...
a
a
(
G
2
1
⋅
⋅
⋅
=
To find G press:
*3.41*7*11*23\BM1/6\
Remember that we can write the above equation this other way:
2*3.4
1
Remember that the
U
key starts a new calculation. The
M
key is only active after pressing
U
,
J
,
\
, or a two-
argument function (e.g.
+
,
/
,
B
,
~Ð
, etc.)
hp calculators
- 4 -
HP 9s Powers and Roots - Version 1.0
