Answer:
Step-by-step explanation:
The rate if increase of side of square is 7cm/s
dL/dt=7
At what area is the area increasing
dA/dt=?
Areas of square is give to be 36cm²
Analysis
Let L be the length of each side of the square, a square has equal side.
Area of square is give as L²
Area=L²
L²=36
i.e L=√36
L=6cm
Therefore at t=0 L=6cm and A=36cm²
A=L²
dA/dL=2L
Given that, dL/dt=7
Multiply the two differential together
dA/dt= dA/dL × dL/dt
dA/dt= 2L × 7
dA/dt= 2×6×7
dA/dt= 84cm²/s
The rate of increase of the square is 84cm²/s
