I=∫−44f(x2)dx=2∫04f(x2)dx {Even function}
=2∫04(4x3−g(4−x))dx
=2(44x4∣04−∫04g(4−x)dx)=512−2I1
I1=∫04g(4−x)dx=∫02g(4−x)dx+∫24g(4−x)dx
Let I2=∫24g(4−x)dx
If 4−x=t then
I2=−∫20g(t)dt=∫02g(t)dt=∫02g(x)dx
So, I1=∫02g(4−x)dx+∫02g(x)dx=0
Hence, I=512