Question
यदि $\,|\alpha |,|\beta |\, < 1,\,\,1 - \alpha + {\alpha ^2} - {\alpha ^3} + ...\infty = {s_1},$ $1 - \beta + {\beta ^2} - {\beta ^3} + ....\infty = {s_2},$ तब $1 - \alpha \beta + {a^2}{\beta ^2} - {a^3}{\beta ^3} + ....\infty \,$ का मान होगा