Homework, 2.8: related rates
p. 180, #19, 24, 28
MAT128, Fall, 2015
Andy Long

#19

A[b_,h_]:=b*h/2
eq=D[A[b[t],h[t]],t]
Solve[A[b,10]==100,b]
Solve[eq==2,b'[t]]

#28

Solve[D[Tan[th[t]]==100/x[t],t],th'[t]]
-100Cos[Pi/6]^2*8/30000