First we use product rule
y=x^2lnx
dy/dx = x^2 d/dx (lnx) + lnx d/dx (x^2)
dy/dx = x^2 (1/x) + lnx (2x)
dy/dx = x + 2xlnx
now taking second derivative:
d2y/dx2 = 1 + 2[x (1/x) + lnx (1)]
d2y/dx2 = 1 + 2[1+lnx]
1+2+2lnx
3+2lnx is the answer
Given:
The radius of the cone = 14 ft
The slant height of the cone = 27 ft
To find the lateral surface area and the total surface area of the given cone.
Formula
The lateral surface area of the cone is
and
The total surface area of the cone is

where,
r be the radius and
l be the slant height of the cone.
Now
Taking r = 14 and l = 27 we get
sq ft
or,
sq ft
Again,
sq ft
or,
sq ft
Hence,
The lateral surface area of the cone is 1187.5 sq ft and the total surface area of the cone is 1803.3 sq ft. Option C.
Answer:
Option A. 
Step-by-step explanation:
step 1
Find the area of the brownie pan
The area of the trapezoid is equal to

step 2
To calculate the number of days, divide the total area of the brownie pan by 30 square centimeters of brownie
so

10/30 or you can symlafife