✓ Mathematica : cpu = 0.0728113 (sec), leaf count = 23
DSolve[-E^(-Sin[x]) + Cos[x]*y[x] + Derivative[1][y][x] == 0,y[x],x]
✓ Maple : cpu = 0.006 (sec), leaf count = 13
dsolve(diff(y(x),x)+y(x)*cos(x)-exp(-sin(x)) = 0,y(x))
Hand solution
Integrating factor
Replacing