Input: dsolve(y(1,x)=cos(x-y))
Write: `dsolve(y(1,x)=cos(x-y))`
Output: $$ dsolve(y^{(1)}(x)=cos(x-y)) == (-2.0)\ acot((-C_1)-x)+x $$ Result:$$(-2.0)\ acot((-C_1)-x)+x$$