integral (4x + 2)^2 dx

cara satu
[tex]\int{(4x+2)^2} \,dx=\int{16x^2+16x+4} \,dx\\=\frac{16}{3}x^3+8x^2+4x+C[/tex]

cara dua
misalkan
[tex]u=4x+2\rightarrow \frac{du}{dx}=4\\dx=\frac{1}{4}dx\\\\\int{(4x+2)^2} \,dx=\frac{1}{4}\int{u^2} \,du\\=\frac{1}{12}u^3+C\\=\frac{1}{12}(4x+2)^3+C[/tex]