Q:

What is De Moivre's Theorem?

A:

Quick Answer

De Moivre's Theorem is a formula that is used to calculate the power of complex numbers. The formula of the theorem states that any real number x and any integer n that (cosx + isinx) to the nth power would equal cos (nx) + isin(nx).

Know More

Full Answer

De Moivre's Theorem is important due to its ability to connect complex numbers and trigonometry. Through expanding the left hand side and then comparing both the real and imaginary parts while assuming that x is real, it is possible to get an expression for cos(nx) and sin(nx).

Although it is a theorem, De Moivre's formula can be proven mathematically through induction for natural numbers and extended to all integers from that induction. There is a single limitation in the theorem - it does not work for non-integer powers.

When an equation has a complex number that is taken to a non-integer power, De Moivre's theorem cannot be used due to the fact that the solution can have many different values. Despite this shortcoming, it is generally accepted that the right-hand side of an expression that meets these standard can still be a possible value of the power.

De Moivre's theorem and the formula that accompanies it is an integral part of trigonometry.

Learn more about Physics

Related Questions

  • Q:

    What is the 3-D distance formula?

    A:

    The 3D, or three-dimensional distance formula is the square root of the sum of the square of the difference between each coordinate point. In a three-dimensional plane, the coordinates are generally written with the variables x, y and z.

    Full Answer >
    Filed Under:
  • Q:

    What is the formula in calculating EMF?

    A:

    Electromotive force, or EMF, is calculated using the formula e = E / Q, where e is the EMF, E is the energy in Joules and Q is the charge. The EMF measures the potential difference between the terminals of a cell when the circuit is switched off.

    Full Answer >
    Filed Under:
  • Q:

    What is the formula for tension in physics?

    A:

    In physics, the tension on a suspended object said to be equal to the weight of the object plus or minus the mass of the object times the acceleration acting on it. In other words, this is the weight of the object plus or minus the force on it, depending on the direction in which the force is acting.

    Full Answer >
    Filed Under:
  • Q:

    What is the formula for hoop stress?

    A:

    Engineers Edge explains that the hoop stress formula is ?a = PDm/2t, where P signifies internal pressure; t is wall thickness; r is internal radius of cylinder; and, Dm equals the mean diameter or outside diameter minus wall thickness. The hoop stress is ?a, as stated by Engineers Edge.

    Full Answer >
    Filed Under:

Explore