求极限lim(t->0+) 1/t^2 ∫(0~t)dx∫(0~t-x)e^(x^2+y^2)dy,高手帮个忙,

f(t²) = ∫[0,t] dx ∫[0,t-x] e^(x²+y²) dy 化为极坐标D:0≤ r ≤ t / (sinθ+cosθ),0≤θ≤ π/2= ∫[0,π/2] dθ ∫[0,t /(sinθ+cosθ)] e^(r²) r dr= ∫[0,π/2] (1/2) [ e^ { t² /(...