Write down the time-independent schrödinger equation of a particle with mass m confined in a central potential -1/r. use spherical coordinates.

2. write down the time-independent schrödinger equation of two particles with masses m_1 and m_2 that are attracted to each other by potential -1/r_12 , where r_12 is the particle-particle distance, namely, r_12 = sqrt((x_1 - x_2)^2+(y_1 - y_2)^2+(z_1 - z_2)^2) , where particle 1’s coordinates are (x_1, y_1, z_1) and particle 2’s coordinates are (x_2, y_2, z_2).