Answer:
(a) 0.198 cm/s (b) 1 cm/s
Step-by-step explanation:
It is given that,
The rate of change of area of a cicle,
(a) The area of a circle is given by :
Differentiate both sides,
(b) Circumference, = 5 cm
Hence,
(a) 0.198 cm/s (b) 1 cm/s
Answer:
Total area of the gray sections of the target is 678 square inches.
Step-by-step explanation:
Given :
Three concentric circles and we have to find the total area of the gray sections.
Area of white circle having radius 1 foot.
⇒ Area of the white circle - Area of the smaller gray circle.
⇒
⇒
⇒ <em> ...1 foot = 12 inches and 0.5 foot = 6 inches</em>
⇒
⇒
⇒ 339.12 square inches
The total area of the gray sections is the area of the bigger gray circle minus the area of the white circle.
Total area of the gray sections:
⇒
⇒ <em> ....where 1.5 foot = 18 inches</em>
⇒
⇒ square inches.
≅ 678 square inches.
The total area of the gray sections of the target, to the nearest square inch is 678.
Option C is the right choice.
Answer:
a) 14x+6
b)12+9x
c)Perimeter= 118 Area=840
Step-by-step explanation:
a) 2*length+ 2*width---> 2(4x+3)+2(3x)=8x+6+6x= 14x+6
b)length* width---> 3x(4x+3)= 12+9x
c) Perimeter----> 14(8)+6= 118
Area--->12()+9(8)=840