Why didn't I find the same answer?

Hi, i try to calculate the math in 2 ways, but i couldn't find the same result, i don't why ?. Here is the problem

% method 1 
a=gamma(3/10)-igamma(3/10,-7/100);
b=-(-1)^(7/10)*10^(3/5);
c=a*b;
% method 2
alpha=0.3;
s=0.1;
t=7;

A=gamma(alpha)-igamma(alpha,-s^2*t);
B=-(-1)^(alpha-1)*(1/s^2)^(alpha);
C=A*B;

result : why ?? but !

What should i do now ?

Answer 1

[DGM]

b and B are not the same. They are conjugate.

B=-(-1)^(alpha-1)*(1/s^2)^(alpha);

In this case (alpha-1) does not equal 0.7.

You're probably thinking of (1-alpha)

[Yamina chbak]

yes that's correct . thanks you.