4–4 Real–Number
Functions
File name 32sii-Manual-E-0424
Printed Date : 2003/4/24 Size : 17.7 x 25.2 cm
Trigonometric Functions
With
x
in the display:
To Calculate:
Press:
Sine of
x
.
N
Cosine of
x
.
Q
Tangent of
x
.
T
Arc sine of
x
.
z
L
Arc cosine of
x
.
z
O
Arc tangent of
x
.
z
R
Note
Calculations with the irrational number
π
cannot be expressed
exactly
by the 12–digit internal precision of the calculator. This
is particularly noticeable in trigonometry. For example, the
calculated sin
π
(radians) is not zero but –2.0676
×
10
–13
, a
very small number close to zero.
Example:
Show that cosine (5
÷
7)
π
radians and cosine 128.57° are equal (to four
significant digits).
Keys: Display: Description:
z
{
}
Sets Radians mode;
RAD
annunciator on.
5
7
)
5
÷
7 in decimal format.
{
M
y
Q
.)
Cos (5/7)
π
.
z
{
}
.)
Switches to Degrees mode (no
annunciator).
128.57
Q
.)
Calculates cos 128.57°, which is
the same as cos (5/7)
π
.
