ATAN

ATAN(number)

Returns the angle in radians for a given tangent ratio.

number

The tangent ratio.

REMARKS

* For an illustrated example refer to the Trigonometric Functions page.
* The inverse of this function is the TAN function.
* This function returns the angle (in radians, between -PI/2 and PI/2) that has a given value as its tangent.
* If "number" is not numeric, then #VALUE! is returned.
* To convert a number from degrees to radians, multiply it by PI/180.
* To convert a number from radians to degrees, multiply it by 180/PI.
* You can use the COS function to return the cosine of an angle.
* You can use the SIN function to return the sine of an angle.
* You can use the TAN function to return the tangent of an angle.
* You can use the ACOS function to return the angle in radians for a given cosine ratio.
* You can use the ASIN function to return the angle in radians for a given sine ratio.
* You can use the RADIANS function to convert from degrees to radians.
* You can use the DEGREES function to convert from radians to degrees.
* You can use the ACOT function to return the arc-cotangent.
* You can use the ATAN2 function to return the arc-tangent of the given x and y co-ordinates.
* For the Microsoft documentation refer to support.microsoft.com

	A
1	=ATAN(-1) = -0.785
2	=ATAN(0.5) = 0.464
3	=ATAN(0) = 0
4	=ATAN(0.5) = 0.464
5	=ATAN(1) = 0.785
6	=ATAN(1000000) = 1.571
7	=ATAN(1)*180/PI() = 45
8	=DEGREES(ATAN(1)) = 45
9	=ATAN(TAN(0.5)) = 0.5
10	=ATAN("text") = #VALUE!

1 - What is the angle in radians for a tangent ratio of -1. This is PI/4.
2 - What is the angle in radians for a tangent ratio of -0.5.
3 - What is the angle in radians for a tangent ratio of 0.
4 - What is the angle in radians for a tangent ratio of 0.5.
5 - What is the angle in radians for a tangent ratio of 1. This is PI/4.
6 - What is the angle in radians for a tangent ratio of 1000000. This is PI/2.
7 - What is the angle in degrees for the tangent ratio of 1.
8 - What is the angle in degrees for the tangent ratio of 1.
9 - What is the inverse of tangent.
10 - When number is not numeric.