var('t')
var('a')
var('b')
var('k')
y=function('y',t)
print desolve(diff(y,t)-a + b*cos(2*pi*t/24)+k*y,[y,t])

Kesarwani Aashita Chandrashekhar, Student, IIT Roorkee Praveen Kumar, Student, IIT Roorkee