When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Exact trigonometric values - Wikipedia

    en.wikipedia.org/wiki/Exact_trigonometric_values

    Similarly / = is a constructible angle because 12 is a power of two (4) times a Fermat prime (3). But π / 9 = 20 ∘ {\displaystyle \pi /9=20^{\circ }} is not a constructible angle, since 9 = 3 ⋅ 3 {\displaystyle 9=3\cdot 3} is not the product of distinct Fermat primes as it contains 3 as a factor twice, and neither is π / 7 ≈ 25.714 ∘ ...

  3. List of trigonometric identities - Wikipedia

    en.wikipedia.org/wiki/List_of_trigonometric...

    A formula for computing the trigonometric identities for the one-third angle exists, but it requires finding the zeroes of the cubic equation 4x 3 − 3x + d = 0, where is the value of the cosine function at the one-third angle and d is the known value of the cosine function at the full angle.

  4. Trigonometric tables - Wikipedia

    en.wikipedia.org/wiki/Trigonometric_tables

    These angles are usually arranged across the top row of the table, while the different trigonometric functions are labeled in the first column on the left. To locate the value of a specific trigonometric function at a certain angle, you would find the row for the function and follow it across to the column under the desired angle. [1]

  5. Trigonometric functions - Wikipedia

    en.wikipedia.org/wiki/Trigonometric_functions

    Basis of trigonometry: if two right triangles have equal acute angles, they are similar, so their corresponding side lengths are proportional.. In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) [1] are real functions which relate an angle of a right-angled triangle to ratios of two side lengths.

  6. Wikipedia:Reference desk/Archives/Mathematics/2008 April 3 ...

    en.wikipedia.org/wiki/Wikipedia:Reference_desk/...

    I did the inverse sine of 1/2 (in rads) and got pi/6 and from there used the quadrant diagram (and divided by 2) to get x = pi/12 and x=5pi/12. However my textbook says that 13pi/12 and 17pi/12 are also solutions and I can't for the life of me figure out why. Any pointers in the right direction would be appreciated.

  7. Table of polyhedron dihedral angles - Wikipedia

    en.wikipedia.org/wiki/Table_of_polyhedron...

    exact dihedral angle (radians) dihedral angleexact in bold, else approximate (degrees) Platonic solids (regular convex) Tetrahedron {3,3} (3.3.3) arccos (⁠ 1 / 3 ⁠) 70.529° Hexahedron or Cube {4,3} (4.4.4) arccos (0) = ⁠ π / 2 ⁠ 90° Octahedron {3,4} (3.3.3.3) arccos (-⁠ 1 / 3 ⁠) 109.471° Dodecahedron {5,3} (5.5.5) arccos ...

  8. Euler's identity - Wikipedia

    en.wikipedia.org/wiki/Euler's_identity

    Euler's formula for a general angle. Euler's identity is a special case of Euler's formula, which states that for any real number x, = ⁡ + ⁡ where the inputs of the trigonometric functions sine and cosine are given in radians. In particular, when x = π,

  9. Special right triangle - Wikipedia

    en.wikipedia.org/wiki/Special_right_triangle

    The 30°–60°–90° triangle is the only right triangle whose angles are in an arithmetic progression. The proof of this fact is simple and follows on from the fact that if α, α + δ, α + 2δ are the angles in the progression then the sum of the angles 3α + 3δ = 180°. After dividing by 3, the angle α + δ must be 60°. The right angle ...