MathematicsGeometry
Triangle Area Calculator (3 Sides)
Calculate triangle area from three sides using Heron's formula. Enter any three known values (sides or area) to find the fourth. Free, accurate, and instant results.
The arctan calculator helps you find the inverse tangent of any real number. Also known as arctangent or tan⁻¹, this trigonometric function returns the angle whose tangent equals your input value. Whether you're working in degrees, radians, or other angular units, this calculator provides instant, accurate results for mathematics, physics, engineering, and navigation applications.
Arctan (inverse tangent) is a trigonometric function that reverses the tangent operation. If tan(θ) = x, then arctan(x) = θ. Unlike arcsin and arccos, arctan accepts any real number as input and returns angles between -π/2 and π/2 radians (-90° to 90°). This range represents the principal values of the inverse tangent function.
In mathematical notation, arctan is written as tan⁻¹(x) or atan(x). The function is fundamental in geometry for finding angles when slopes or ratios are known, in calculus for integration, and in engineering for phase angle calculations and coordinate transformations.
Using the calculator is straightforward. Enter your known value in either field. If you know the x value (any real number), enter it to calculate the corresponding angle. If you know the angle, enter it to find the tangent value. Select your preferred angle unit from the dropdown menu—degrees, radians, gradians, or turns. The calculator automatically updates results as you type.
Arctan is widely used to calculate slope angles in geometry and construction. In physics, it appears in vector analysis, projectile motion, and electromagnetic field calculations. Navigation systems use it for bearing calculations and coordinate conversions. Computer graphics rely on arctan for rotation matrices and camera orientation. In engineering, it's essential for impedance phase angles, control systems, and signal processing applications like phase-locked loops.
Arctan accepts any real number, positive or negative, unlike arcsin and arccos
The output angle will always be between -90° and 90° (-π/2 and π/2 radians)
Use radians for calculus and advanced mathematics, degrees for everyday applications
Common values: arctan(0) = 0°, arctan(1) = 45°, arctan(∞) approaches 90°
What is the domain of arctan?
The domain of arctan is all real numbers (-∞, ∞). Unlike arcsin and arccos, there are no restrictions on the input value.
What is atan2 and how does it differ from arctan?
The atan2 function takes two arguments (y, x) and returns angles in the full range [-π, π] by considering the signs of both inputs. Standard arctan only returns values in [-π/2, π/2]. Use atan2 when you need to determine angles in all four quadrants.
Calculate triangle area from three sides using Heron's formula. Enter any three known values (sides or area) to find the fourth. Free, accurate, and instant results.
Calculate inverse cosine (arccos) values instantly. Enter any value between -1 and 1 to find the corresponding angle in degrees or radians. Free arccos calculator.
Calculate inverse sine (arcsin) values instantly. Enter any value between -1 and 1 to find the corresponding angle in degrees or radians. Free arcsin calculator.