Let I1=∫0xetx.e-t2dt and I2=∫0xe-t2/4dt where x>0, then the value of I1I2 is
(2)
I1=∫0xex24-(t-x2)2dt=ex24∫-x2x2e-z2dz t-x2=z
=2ex24∫0x2e-z2dz
I2=∫0xe-t24dt
Let t2=z =∫0x2e-z2×2dz