how can i integrate this function ?

Hello everybody , i have the bellow function , i want to integrate it from a to b

but the result is not complete , there is no result for a , the code for this

function is :

syms y

syms bx

syms v

syms a

syms b

% c is constant

f= y / ((bx - y)^2/v + 1)^(v/2)

z = int ( f , a,b , y )

***

the result after i run it in matlabe is :

z =

-(y*(b - y))/((bx - y)^2/v + 1)^(v/2)

Answer 1

[Steven Lord]

You're close. Look at the documentation for the int function. Pay close attention to the order of the input arguments and what each input argument represents.

[elham kreem]

i want to thanks for you

i applied this code , but no result

z = int ( f , y , [a,b] )

the result was :

z =

int(y/((bx - y)^2/v + 1)^(v/2), y, a, b)

[Torsten]

Where did you find this syntax with "[a,b]" for "int" ? It's wrong.

[elham kreem]

from help of matlab , as :

int(expr,var,a,b) computes the definite integral of expr with respect to var from a to b. If you do not specify it, int uses the default variable determined by symvar. If expr is a constant, then the default variable is x.

int(expr,var,[a,b]), int(expr,var,[a b]), and int(expr,var,[a;b]) are equivalent to int(expr,var,a,b).

** If I'm imposed values for a and b , also , the result as the same

[elham kreem]

and if i omit a ,b , the result is :

int(y/((bx - y)^2/v + 1)^(v/2), y)

[Torsten]

This indicates that MATLAB was not able to find an analytical expression for the integral. You will have to insert numerical values for b and v, numerical values for the limits a and b and use "integral" for a numerical approximation of the integral.

[elham kreem]

thank you