MATH 152 Activity 8 (Section 9.4)
Directions: Put your group name, section number and members present on the answer sheet. Use scratch paper for
work, meaning only put the answers on the answer sheet. Turn in only ONE answer sheet per group. Calculators are
allowed and you may use your notes and textbook. Failure to follow these instructions will result in a 1 point deduction.
Neat handwriting is expected.
1. Find the surface area obtained by rotating the curve y = 2x3 , 0 ≤ x ≤ 2 about the x axis.
√
2. Find the surface area obtained by rotating the curve y = 3 x, 1 ≤ y ≤ 2 about the y axis.
3. The curve y = ln(x + 1), 0 ≤ x ≤ 4 is revolved about the x axis. Set up but do not evaluate an integral that gives
the surface area using two methods:
(i) An integral with respect to x.
(ii) An integral with respect to y.
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