tolong bantu jawab soal no 1 ttg volume benda putar dengan cara penyelesaiannya

cari batas integral
x² - 2x = 0
x(x - 2) = 0
x = 0   dan   x = 2
===========================
L = π ∫ y² dx {0...2}

= π ∫ (x² - 2x)² dx {0...2}
= π ∫ x⁴ - 4x³ + 4x²  dx {0...2}
= π [ x⁵/5 - x⁴ + 4x³/3 ] {2...0}
= π [2⁵/5 - 2⁴ + 4(2³)/3 - 0]
= π [6(2⁴)/15 + 10(2⁴)/15 - 15(2⁴)/15]
= π [2⁴/15]
= (16/15) π satuan volume