Exponential Function

DOWNLOAD Mathematica Notebook EXPLORE THIS TOPIC IN the MathWorld Classroom
ExpReal
Min Max
Powered by webMathematica
ExpReImAbs
Min Max
Re
Im Powered by webMathematica

The exponential function is the entire function defined by

 exp(z)=e^z,
(1)

where e is the solution of the equation int_1^xdt/t so that e=x=2.718.... exp(z) is also the unique solution of the equation df/dz=f(z) with f(0)=1.

The exponential function is implemented in the Wolfram Language as Exp[z].

It satisfies the identity

 exp(x+y)=exp(x)exp(y).
(2)

If z=x+iy,

 e^z=e^(x+iy)=e^xe^(iy)=e^x(cosy+isiny).
(3)

The exponential function satisfies the identities

e^x=coshx+sinhx
(4)
=sec(gdx)+tan(gdx)
(5)
=tan(1/4pi+1/2gdx)
(6)
=(1+sin(gdx))/(cos(gdx)),
(7)

where gdx is the Gudermannian (Beyer 1987, p. 164; Zwillinger 1995, p. 485).

The exponential function has Maclaurin series

 exp(x)=sum_(n=0)^infty(x^n)/(n!),
(8)

and satisfies the limit

 exp(x)=lim_(n->infty)(1+x/n)^n.
(9)

If

 a+bi=e^(x+iy),
(10)

then

y=tan^(-1)(b/a)
(11)
x=ln{bcsc[tan^(-1)(b/a)]}
(12)
=ln{asec[tan^(-1)(b/a)]}.
(13)

The exponential function has continued fraction

 e^z=1/(1-z/(1+z/(2-z/(3+z/(2-z/(5+z/(2-...)))))))
(14)

(Wall 1948, p. 348).

ExpInv
ExpInvReImAbs
Min Max
Re
Im Powered by webMathematica

The above plot shows the function e^(1/z) (Trott 2004, pp. 165-166).

Integrals involving the exponential function include

int_0^(2pi)e^(e^(it))dt=2pi
(15)
int_0^(2pi)e^(e^(it)-it)dt=2pi
(16)

(Borwein et al. 2004, p. 55).

Wolfram Web Resources

Mathematica »

The #1 tool for creating Demonstrations and anything technical.

Wolfram|Alpha »

Explore anything with the first computational knowledge engine.

Wolfram Demonstrations Project »

Explore thousands of free applications across science, mathematics, engineering, technology, business, art, finance, social sciences, and more.

Computerbasedmath.org »

Join the initiative for modernizing math education.

Online Integral Calculator »

Solve integrals with Wolfram|Alpha.

Step-by-step Solutions »

Walk through homework problems step-by-step from beginning to end. Hints help you try the next step on your own.

Wolfram Problem Generator »

Unlimited random practice problems and answers with built-in Step-by-step solutions. Practice online or make a printable study sheet.

Wolfram Education Portal »

Collection of teaching and learning tools built by Wolfram education experts: dynamic textbook, lesson plans, widgets, interactive Demonstrations, and more.

Wolfram Language »

Knowledge-based programming for everyone.