Answer:
12.57
Step-by-step explanation:
the formula for the area of a circle is 
the diameter is 2 times the radius, so dividing it by 2 gives you a radius of 2
substitute the 2 for the r in the formula and solve

4
≈12.57
Answer:
10.12
Step-by-step explanation:
5.6x2
Answer:
The value of x that maximizes the volume enclosed by this box is 0.46 inches
The maximum volume is 3.02 cubic inches
Step-by-step explanation:
see the attached figure to better understand the problem
we know that
The volume of the open-topped box is equal to

where

substitute

Convert to expanded form

using a graphing tool
Graph the cubic equation
Remember that
The domain for x is the interval -----> (0,1)
Because
If x>1
then
the width is negative (W=2-2x)
so
The maximum is the point (0.46,3.02)
see the attached figure
therefore
The value of x that maximizes the volume enclosed by this box is 0.46 inches
The maximum volume is 3.02 cubic inches
Answer:
9/2
Step-by-step explanation:
perpendicular lines have slopes that are opposite and reciprocal
the reciprocal of -2/9 is 9/2