The formula below gives the surface area S of a human body (in square meters) in terms of its weight W (in kilograms) and its height H (in centimeters).

S = 0.007184(W^0.425)(H^0.725)
Compute SW and SH when W = 100 kg and
H = 180 cm.
SW = ?
SH = ?
NOTE: I took the derivative of 0.007184 and multiply it by the derivative (100^.425)(180^.725)
but it still says it is wrong. please help me out.

1 answer

dS/dW = (.425)(.007184)W^.425-1 (H^.725)

dS/dW =0.0030532W^-.575(H^.725)

dS/dW = 0.0030532H^.725/W^.575
0.0030532(180)^.725/100^.575
dS/dH = (.725)(.007184)W^.425H^.725-1

dS/dH = .0052084 W^.425H^-.275
dS/dH = .0052084 W^.425/H^.275

dS/dH = 0.0052084(100)^.425/180^.275