S=2ab+2bc+2ac, so from the knowledge of calculus.

Ds/dt = 2 * da/dt * b+2 * db/dt * a+2 * db/dt * c+2 * DC/dt * b+2 * da/dt * c+2 * DC/dt * a, at this time a, b, c, da/dt, db/a.

Therefore, T=abc.

DT/DT = BC * da/DT+AC * db/DT+ab * DC/DT。 Similarly, if the above known values are substituted, dt/dt = m3/sec.

the second question

Because the volume v = π r 2 * h

Sensitivity is described by small changes in parameter values, which will lead to changes in volume.

Derive v from r, dV=2πrh*dr, and substitute it into the relevant value, dv =10 π * dr.

Derive v from h, DV = π r 2 * DH, and substitute it into the correlation value, dV=2π*dh.

Comparing the coefficients of the above two expressions, we can know that the sensitivity of volume to radius change is much greater than that of height change.

I don't know what the second question means.

My understanding is to design a container with the same volume but balanced radius and high sensitivity.

For a jar with a radius of 1.5 inches and a height of 20/9 inches, you can say that the volume of this jar is the same as that of the last jar. After calculation, it is found that the sensitivity of the two parameters to volume is not much different.