fresnels
Fresnel sine integral function
Syntax
Description
fresnels( returns the Fresnel sine integral of
z)z.
Examples
Fresnel Sine Integral Function for Numeric and Symbolic Arguments
Find the Fresnel sine integral function for these numbers. Since these are not symbolic objects, you receive floating-point results.
fresnels([-2 0.001 1.22+0.31i])
ans = -0.3434 + 0.0000i 0.0000 + 0.0000i 0.7697 + 0.2945i
Find the Fresnel sine integral function symbolically by converting the numbers to symbolic objects:
y = fresnels(sym([-2 0.001 1.22+0.31i]))
y = [ -fresnels(2), fresnels(1/1000), fresnels(61/50 + 31i/100)]
Use vpa to approximate the results:
vpa(y)
ans = [ -0.34341567836369824219530081595807, 0.00000000052359877559820659249174920261227,... 0.76969209233306959998384249252902 + 0.29449530344285433030167256417637i]
Fresnel Sine Integral for Special Values
Find the Fresnel sine integral function for special values:
fresnels([0 Inf -Inf i*Inf -i*Inf])
ans = 0.0000 + 0.0000i 0.5000 + 0.0000i -0.5000 + 0.0000i 0.0000 - 0.5000i... 0.0000 + 0.5000i
Fresnel Sine Integral for Symbolic Functions
Find the Fresnel sine integral for the function exp(x) +
2*x:
syms x f = symfun(exp(x)+2*x,x); fresnels(f)
ans(x) = fresnels(2*x + exp(x))
Fresnel Sine Integral for Symbolic Vectors and Arrays
Find the Fresnel sine integral for elements of vector
V and matrix M:
syms x V = [sin(x) 2i -7]; M = [0 2; i exp(x)]; fresnels(V) fresnels(M)
ans = [ fresnels(sin(x)), fresnels(2i), -fresnels(7)] ans = [ 0, fresnels(2)] [ fresnels(1i), fresnels(exp(x))]
Plot Fresnel Sine Integral Function
Plot the Fresnel sine integral function from x = -5 to x = 5.
syms x fplot(fresnels(x),[-5 5]) grid on

Differentiate and Find Limits of Fresnel Sine Integral
The functions diff and
limit handle expressions containing
fresnels.
Find the fourth derivative of the Fresnel sine integral function:
syms x diff(fresnels(x),x,4)
ans = - 3*x*pi^2*sin((pi*x^2)/2) - x^3*pi^3*cos((pi*x^2)/2)
Find the limit of the Fresnel sine integral function as x tends to infinity:
syms x limit(fresnels(x),Inf)
ans = 1/2
Taylor Series Expansion of Fresnel Sine Integral
Use taylor to expand the Fresnel sine integral
in terms of the Taylor series:
syms x taylor(fresnels(x))
ans = (pi*x^3)/6
Simplify Expressions Containing fresnels
Use simplify to simplify expressions:
syms x simplify(3*fresnels(x)+2*fresnels(-x))
ans = fresnels(x)
Input Arguments
More About
Algorithms
The fresnels(z) function is analytic throughout the complex plane. It
satisfies fresnels(-z) = -fresnels(z), conj(fresnels(z)) = fresnels(conj(z)), and fresnels(i*z) = -i*fresnels(z) for all complex values of z.
fresnels(z) returns special values for z = 0, z = ±∞, and z = ±i∞ which are 0, ±5, and ∓0.5i. fresnels(z) returns symbolic function calls for all
other symbolic values of z.
Version History
Introduced in R2014a