y&#39；= e^xsinx + e^xcosx = e^x(sinx + cosx)。y&#39；&#39；= e^x(sinx + cosx) + e^x(cosx - sinx) = e^x*2cosx。y&#39；&#39；&#39；= e^x*2cosx + e^x*(-2sinx) = e^x(2cosx - 2sinx)。y(4) = e^x(2cosx - 2sinx) + e^x*(-2sinx - 2cosx) = e^x(-4sinx)。因此。y(2k) = e^x*(2^k)*sin(x + kπ/2)。y(2k-1) = e^x*k*[sin(x + (2k-1)π/2) - cos(x + (2k-1)π/2)]。