已知二维随机变量(X，Y)的联合概率密度

利用MATLAB的符号运算功能，求待定系数A；P{X>1，Y>2}；边缘分布

-Known two-dimensional random variable (X, Y) the joint probability density function using MATLAB' s symbolic computation, seeking undetermined coefficients A　P {X>　1, Y>　2}　marginal distribution