MATH 122
Test II
1.(10) ò[([Ö(1-x2)])/( x2)]dx
2.(10) ò[(3x)/( [Ö(4+x2)])]dx
3.(30) Find the volumes of the solids of revolution. (Set up integrals.)
Tell the method you use. Use disks/washers at least once. Use shells at
least once.
a) Region I about the x-axis
b) Region II about the vertical line x = [(p)/ 2]
c) Region III about the horizontal line y = 2.
4.(10) A 100 pound load is being pulled up a 30 foot tower by a chain
weighing 4 pounds per foot. Set up integrals to
a) find the amount of work needed to raise the load the first 10 feet.
b) find the amount of work needed to raise the load the last 10 feet.
5.(10) A flood gate in a dam is in the shape of half a disk (think of the
top half of a circle). The half disk has a radius of 5 ft. The top of the
gate is located 20 feet below the water line. Set up an integral to find
the force due to water pressure on the gate.
6.(10) Find the cubic Taylor polynomial P3(x) for f(x) = sinx expanded
about a = [(p)/ 3].
7.(10) a) Calculate the third partial sum, s3, for the series åk = 1¥[2/( k2+1)]. (Nothing fancy here; I am checking to
see if you know the definition of partial sum.)
b) This series is not telescoping. Why not?
c) This series is not geometric. Why not?
8.(10) Suppose the series åk = 1¥ ak has partial sums sn = [(3n(n+1))/( 4n2-1)].
a) Is the series åk = 1¥ ak convergent or divergent? Explain.
b) If convergent, what is the sum of the series? Explain.