enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 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.

  3. De Moivre's formula - Wikipedia

    en.wikipedia.org/wiki/De_Moivre's_formula

    The expression cos x + i sin x is sometimes abbreviated to cis x. The formula is important because it connects complex numbers and trigonometry . By expanding the left hand side and then comparing the real and imaginary parts under the assumption that x is real, it is possible to derive useful expressions for cos nx and sin nx in terms of cos x ...

  4. Rectangular function - Wikipedia

    en.wikipedia.org/wiki/Rectangular_function

    Plot of normalized ⁡ function (i.e. ⁡ ()) with its spectral frequency components.. The unitary Fourier transforms of the rectangular function are [2] ⁡ = ⁡ = ⁡ (), using ordinary frequency f, where is the normalized form [10] of the sinc function and ⁡ = ⁡ (/) / = ⁡ (/), using angular frequency , where is the unnormalized form of the sinc function.

  5. Trigonometry - Wikipedia

    en.wikipedia.org/wiki/Trigonometry

    Trigonometry has been noted for its many identities, that is, equations that are true for all possible inputs. [83] Identities involving only angles are known as trigonometric identities. Other equations, known as triangle identities, [84] relate both the sides and angles of a given triangle.

  6. Proofs of trigonometric identities - Wikipedia

    en.wikipedia.org/wiki/Proofs_of_trigonometric...

    This geometric argument relies on definitions of arc length and area, which act as assumptions, so it is rather a condition imposed in construction of trigonometric functions than a provable property. [2] For the sine function, we can handle other values. If θ > π /2, then θ > 1. But sin θ ≤ 1 (because of the Pythagorean identity), so sin ...

  7. Unit circle - Wikipedia

    en.wikipedia.org/wiki/Unit_circle

    Thus, by the Pythagorean theorem, x and y satisfy the equation + = Since x 2 = (−x) 2 for all x, and since the reflection of any point on the unit circle about the x - or y-axis is also on the unit circle, the above equation holds for all points (x, y) on the unit circle, not only those in the first quadrant.

  8. Stem cell therapy to correct heart failure in children could ...

    www.aol.com/stem-cell-therapy-correct-heart...

    Doctors and specialists at the Murdoch Children's Research Institute in Melbourne, Australia, are studying and reprogramming the potential of the blood to treat heart failure in children.

  9. Fraunhofer diffraction equation - Wikipedia

    en.wikipedia.org/.../Fraunhofer_diffraction_equation

    Diffraction geometry, showing aperture (or diffracting object) plane and image plane, with coordinate system. If the aperture is in x ′ y ′ plane, with the origin in the aperture and is illuminated by a monochromatic wave, of wavelength λ, wavenumber k with complex amplitude A(x ′,y ′), and the diffracted wave is observed in the unprimed x,y-plane along the positive -axis, where l,m ...