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METBD 050
Trigonometry Functions
In Excel, three trigonometry functions (SIN, COS, and TAN) and three inverse trig functions
(ASIN, ACOS, and ATAN) are available for use in cell formulas. There are also two conversion
functions, RADIANS for converting degrees into radians and DEGREES for converting radians
into degrees.
Trig Functions:
Each of the trig functions has an angle for an argument. This can be a single value, or the result
of a mathematical expression or the result of a cell formula.
SIN(angle)
COS(angle)
TAN(angle)
In all of the trig functions, the angle is assumed to be in units of radians. So, if you want to find
the sin, cos or tan of an angle given in degrees, it must be converted into radians. This operation
is done with the RADIANS function.
Example:
Find the sine of thirty degrees.
Angle in degrees
=SIN(RADIANS(30))
The radians
function returns
.5235988 radians
=SIN(.5235988)
This is the
same as
The value displayed in the cell is 0.5 which is the sine of thirty degrees. This method works for all
three of the trig functions.
Inverse Trig Functions:
Each of the inverse trig functions has a number for an argument. This can be a single value, or
the result of a mathematical expression or the result of a cell formula.
ASIN(number)
ACOS(number)
ATAN(number)
These functions return an angle in units of radians. So, if you want to find the inverse sine,
inverse cosine or inverse tangent of a number to get an angle in degrees, the result has to be
converted to degrees with the DEGREES function.
Example:
Find the angle whose tangent is 1.2.
Converts the angle in
radians into degrees
=DEGREES(ATAN(1.2))
Returns an angle
in radians
The angle returned is 50.1944 degrees.