Microsoft Office Tutorials and References

In Depth Information

**ATAN**

ATA
The
ATAN
function returns the arctangent of a number. The arctangent is the angle in which

tangent is number. The returned angle is given in radians in the range –pi/2 to pi/2.

=ATAN(number)

The
NUMBER
argument is the tangent of the angle you want.

As with all normal trigonometric functions in Excel, you can convert the result from radians

to degrees by multiplying it by 180/PI().

Notice the example in Figure 10.5 where
ATAN(0.5)
equals
0.4636
.

Where the number is the desired tangent angle.

NUMBER

Figure 10.5

The
ATAN
function

generates the arctangent

of a number.

ATAN2

The
ATAN2
function returns the four-quadrant arctangent of the specified x- and y-coordinates.

The arctangent is the angle from the x-axis to a line containing the origin (0, 0) and a point

with coordinates (x, y). The angle is given in radians between –pi and pi, excluding –pi.

=ATAN2(x,y)

The argument
x
is the x-coordinate of the point and the argument
y
is the y-coordinate of the

point. Notice the example in Figure 10.6.

This is the x-coordinate of the point.

X_NUM

This is the y-coordinate of the point.

Y_NUM