tentukan volume benda putar mengelilingi sumbu y

y=y
2x²=-x+3
2x²+x-3=0
x12= [ -1 +- √1²-4(2)(-3) ]/4
x12= [ -1 +- √25 ]/4
x12= [ -1 +- 5]/4
x1 = -6/4 = -3/2
x2 = 4/4 = 1
dbatasi sumbu y maka batasnya [0,1]
V = pi int[0,1] (-x+3)² - (x²)² dy
= pi int[0,1] (x² -6x +9)-x⁴ ) dy
=pi (1/3x³ - 3x² + 9x - 1/5x^5) [0,1]
= pi (1/3-3+9-1/5) - pi(0)
= pi (5/15-3/15+6)
= (6+2/15) pi