EULER’S FORMULA FOR COMPLEX EXPONENTIALS
math.gmu.edu › ~rsachs › m116EULER’S FORMULA FOR COMPLEX EXPONENTIALS According to Euler, we should regard the complex exponential eit as related to the trigonometric functions cos(t) and sin(t) via the following inspired definition: eit = cos t+i sin t where as usual in complex numbers i2 = ¡1: (1) The justification of this notation is based on the formal derivative of both sides,
Lecture 5. Complex Numbers and Euler’s Formula
www.math.ubc.ca › ~yxli › m152_L5_20175.3 Complex-valued exponential and Euler’s formula Euler’s formula: eit= cost+ isint: (3) Based on this formula and that e it= cos( t)+isin( t) = cost isint: cost= eit+ e it 2; sint= e e it 2i: (4) Why? Here is a way to gain insight into this formula. Recall the Taylor series of et: et= X1 n=0 tn n!: Suppose that this series holds when the exponent is imaginary.
Euler's formula - Wikipedia
https://en.wikipedia.org/wiki/Euler's_formulaThis formula can be interpreted as saying that the function e is a unit complex number, i.e., it traces out the unit circle in the complex plane as φ ranges through the real numbers. Here φ is the angle that a line connecting the origin with a point on the unit circle makes with the positive real axis, measured counterclockwise and in radians.