Find the general solutions of the following differential equations YY '- x + 1 = 0, y'sinx = ylny, cosxsinxdx sinxcosydy = 0,

Find the general solutions of the following differential equations YY '- x + 1 = 0, y'sinx = ylny, cosxsinxdx sinxcosydy = 0,

Note that: YDY = dy ^ 2 / 2, xdx = DX ^ 2 / 2, so it is written in the form of total differential: D (y ^ 2 / 2-x ^ 2 / 2 + x) = 0. The general solution y ^ 2 / 2-x ^ 2 / 2 + x = C is obtained by left and right simultaneous integration, where C is an arbitrary constant. 2, both ends of the equation are multiplied by DX / y