Trigonometry Calculator

  • Cos 2 Theta Calculator
    Compute cos(2θ) for any angle in degrees or radians using the double-angle identity cos(2θ)=cos²θ−sin²θ. Shows cos θ and sin θ too.
  • Complex Number to Rectangular Form Calculator
    Convert a complex number from polar form (r, θ) to rectangular form a + bi. Enter magnitude and angle in degrees or radians for instant results.
  • Complex Number to Trigonometric Form Calculator
    Convert a complex number a + bi to trigonometric (polar) form r(cos θ + i sin θ). Get the modulus r and argument θ in degrees and radians instantly.
  • Complex Number to Polar Form Calculator
    Convert a complex number a + bi to polar form. Get magnitude r and angle θ in degrees and radians instantly, with the full formula explained.
  • Triangle Area Calculator (SAS)
    Calculate the area of a triangle from two sides and their included angle (SAS) using Area = ½·a·b·sin(C). Fast, accurate, free.
  • Triangle Angle Calculator
    Find all three angles of a triangle from its three side lengths using the law of cosines. Free SSS triangle angle calculator with worked example.
  • Inverse Cosine Calculator
    Enter a cosine value between -1 and 1 to compute the inverse cosine (arccos) and see the corresponding angle in degrees and radians instantly.
  • Right Triangle Side and Angle Calculator
    Find the hypotenuse, angles, area and perimeter of a right triangle from its two legs using the Pythagorean theorem and trigonometry.
  • Cosine Calculator
    Enter an angle in degrees to get the cosine value instantly, plus the angle converted to radians. Simple tool for quick trigonometry.
  • Reference Angle Calculator
    Find the reference angle of any angle in degrees or radians. Instantly see the normalized angle, its quadrant, and the acute reference angle.
  • Supplementary Angles Calculator
    Find the supplementary angle instantly. Enter any angle in degrees and get its supplement using supplement = 180 − angle. Free, fast, and accurate.
  • Clock Angle Calculator
    Calculate the exact angle between the hour and minute hands of an analog clock for any time using the standard 30H − 5.5M formula.
  • Coterminal Angle Calculator
    Find coterminal angles in degrees or radians. Get the smallest positive and negative coterminal angles using angle ± 360°n or ± 2πn.
  • Central Angle Calculator
    Find the central angle of a circle from arc length and radius. Get the angle instantly in both radians and degrees with this free calculator.
  • Complementary Angles Calculator
    Find the complementary angle instantly. Enter any angle and get its complement (90 − angle) in degrees. Free, accurate geometry calculator.
  • Angle of Right Triangle Calculator
    Find the acute angle of a right triangle from any two sides using arctan, arcsin, or arccos. Get the result in degrees and radians instantly.
  • Area of an Oblique Triangle Calculator
    Find the area of any oblique triangle from two sides and the included angle using Area = ½·a·b·sin(C). Fast, accurate SAS area calculator.
  • Involute Function Calculator
    Calculate the involute function inv(α) = tan(α) − α for any angle in degrees or radians. Essential for gear and spline tooth geometry design.
  • Unit Circle Calculator
    Find the (x, y) coordinates on the unit circle for any angle in degrees or radians. Computes cos θ, sin θ, and tan θ instantly.
  • Sum and Difference Identities Calculator
    Compute sin(a±b) and cos(a±b) instantly using the trigonometric sum and difference identities. Enter angles in degrees or radians.
  • Inverse Trigonometric Functions Calculator
    Compute arcsin, arccos and arctan online. Enter a value to find the angle θ in both degrees and radians instantly with this free calculator.
  • Power Reducing Calculator
    Apply the power-reducing trig identities to find sin²θ, cos²θ and tan²θ from any angle in degrees or radians. Free, instant, step-shown results.
  • Phase Shift Calculator
    Calculate the phase shift, period, amplitude, and vertical shift of a sine or cosine function y = A·sin(Bx − C) + D instantly.
  • Double Angle Formula Calculator
    Compute sin(2θ), cos(2θ), and tan(2θ) from any angle in degrees or radians using the trigonometric double-angle identities, instantly.

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