As written, your equation for H is ambiguous. I think it's:
H = 33(10√(v) -10.45v) = 330v1/2 - 344.85v
a) Differentiate using the chain and power rules:
dH/dv = 330·(1/2)(v)-1/2 - 344.85
dH/dv is the rate at which a person's body heat loss changes as the wind speed changes.
b) Plug v = 2 then v = 5 into dH/dv and compute the answers