Moment Area theorem problem. please help

I've been trying to solve the following question for 2 days now and i can't seem to be able to. can someone help me please ?

For the beam shown in Figure 3, the support at A is fully fixed. The beam is tapered however you may consider it to be a beam of 3 varying sections.

Take:
Beam A to B as having 3 times the I value of beam D to end, Beam B to D as having 1.5 times the I value of beam D to end and Beam D to end is 310 UB 46.2 with I = 100 x 106 mm4. Tip: this may be easier to solve using superposition.

differential equation: Show that if f and f' are continuous on a ≤ x ≤ b then f and f' are linearly independent on a ≤ x ≤ b

Show that if f and f' are continuous on a ≤ x ≤ b and f(x) is not zero for all x on a ≤ x ≤ b,
then f and xf are linearly independent on a ≤ x ≤ b.

thermo

A spherical container of negligible thickness holding a hot fluid at 1400
and having
an outer diameter of 0.4 m is insulated with three layers of each 50 mm thick
insulation of k1 = 0.02: k2 = 0.06 and k3 = 0.16 W/mK. (Starting from inside). The
outside surface temperature is 300C. Determine (i) the heat loss, and (ii) Interface
temperatures of insulating layers.

need explaination plss..

Volume by integration and finding the centroid

please help me with this!!!
Im really having hard time getting this.
Region 1 is bounded by the x axis, the line x=1 and the curve y=x^2. Region 2 is bounded by the two curves y=x^2 and x=y^2. Region 3 is bounded by the y axis, the line y=1 and the curve x=y^2. Find the volume and centroid of the solid generated when the indicated region is revolved about the given line:
A. Region 1 is revolved about y axis
Region 1 is revolved about x axis
B. Region 2 is revolved about y axis
Region 2 is revolved about x axis