$\int_0^1 2\pi x \sqrt{1+4x^2} dx$

$\int_0^1 \pi x^2 \sqrt{1+x^2} dx$

$\int_0^1 2\pi x^2 \sqrt{1+4x^2} dx$

$\int_0^1 2\pi \sqrt{1+4x^2} dx$