Casio fx-3800P - Page 13

6-6
Rectangular
to
polar
co-ordinates
conversion
Formula:
r=./x?
+
y?
9
=
tan".
(_180°<6<180°)
Ex.)
Find
the
length
r
and
angle
@
in
radian
when
the
point
P
is
shown
as
x
=
1
and
y
=
\/3
in
the
rectangular
co-ordinates,
OPERATION
READ-OUT
"RAD"
(
(wane)
(5)
)
tame
ae
[3
Jun
SHIFT
[1047197551
|
(@
in
radian)
6-7
Polar
to
Rectangular
co-ordinates
conversion
Formula:
x
=
r-cos@
y=r-sing
Ex.)
Obtain
the
values
of
x
and
y
when
the
point
P
is
shown
as
6
=
60°
and
length
r
=
2
in
the
polar
co-ordinates.
OPERATION
READ-OUT
eas
“DEG”
(
(69
(@))
2GE3608)
1.
‘ix
1.732050808
__
|
(y)
6-8
Applications
™
Decibel
(dB)
conversion
Ex.)
How
many
dB
of
amplifier
gain
is
in
an
amp
with
5mW
of
input
power
and
43W
of
output
power?
=
Formula:
dB
=
10-log,,
P,
:
Input
power
(W)
P,
:
Output
power
(W)
OPERATION
READ-OUT
_
Fc
ee
OUT
108)
4385@300me
39.34498451
(dB)
®
Parabolic
movement
Ex.)
Obtain
the
height
of
a
ball
3
seconds
after
throwing
it
at
a
50°
angle
and
at
an
initial
velocity
of
30
m/sec.
(not
calculating
air
resistance),
Formula:
h
=
Vot
sina
—
$
gt’
Height
of
ball
at
T
seconds
after
thrown
(m)
Initial
velocity
(m/sec.)
Time
(sec.)
Throwing
angle
to
level
surface
Gravitational
acceleration
(9.8
m/sec.?)
Vo
gor~e>
°
OPERATION
READ-OUT
“DEG”
(
(ook)
(4)
)
3083850881828908a3—7ea
24.84399988
(m)
®=Cycle
of
a
conical
pendulum
Ex.)
How
many
seconds
is
the
cycle
of
a
conical
pendulum
with
a
cord
length
of
30
cm
and
maximum
swing
angle
of
90°?
0
{*cos
-5
“ULI14,
LISLAL
Perulacre
“<2
“0
Cpe
ph
T
:
Cycle
(sec.)
|
ke
¢
:
Cord
length
(m)
9
:
Maximum
cord
swing
angle
y
9
:
Gravitational
acceleration
(9.8
m/sec.?
)
a
OPERATION
READ-OUT
“DEG”
{
(wong)
(44)
)
282
BOO38090829e@B9FsHeB
0.924421332
(sec.)
®
Triangle
Ex.)
Calculate
the
interior
angle
(@)
and
area
(S)
of
the
triangle
when
the
lengths
of
three
sides
(a,
b
and
c)
are
given.
@:18m,
b:
21m,
¢:
12m
a
Cc
:
at
a?
+
bh?
=
ce
Formula:
cos@
oR
Brat
oe
b
S$
=
7ab
sing
—24-