
partial derivative...
a)assume we have a cylinder ( with a top ) of height h and base radius r. if the top, bottom and wall costs per square meter are a, b and w dollars respectively, find the cost function K ( h, r, a, b, w )that gives the total material cost as a function of h, r, a, b, w
b)find all 5 partial derivative of the function K
how do i begin this question?
surface area= 2 (pi)rh + 2(Pi)r^2
top=a= (pi)r^2 bottom= b= (pi) r^2 wall=w=2(pi)r h
dk/dr= 2(pi)h + 4(pi)r
dk/dh= 2(pi)r
TC= a(dk/dr)+ b(dk/dr) + w(dk/dr)(dk/dh) ?
help please(Crying)(Thinking)

Is this how its done?
a)Total cost=apir^2 +bpir^2 +2wpirh
\
b)
dk/dr= 2apir + 2bpir + 2wpih
dk/dh=2wpir
dk/da= pir^2
dk/db= pir^2
dk/dw=2pirh