I have the following integral and I try to solve this integral by incomplete beta function;
$$\int_{0}^{-d}y^{a}\left(1-y\right)^{-\alpha}dy=\frac{\left(-d\right)^{a+1}}{a+1}{}_{2}F_{1}\left(a+1,2-\alpha;a+2;-d\right)$$
My doubt is the negative value of upper bound.
I guess that even from the beginning, the result of an integral will not change if I reverse the bounds by putting a negative sign but in this but in this case,
I can not figure out how to write the hypergeometric function as the integral would be
$$-\int_{-d}^{0}y^{a}\left(1-y\right)^{-\alpha}dy$$
How should I proceed in this case ?