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ohaa [14]
3 years ago
10

The radius of a coin is 20 cm, find its surface area. (12.57 cm)​

Mathematics
1 answer:
zmey [24]3 years ago
5 0

Answer:

Step-by-step explanation:

assume the coin is circular.

i think radius=2.0 cm

∵ 20 cm is too big for a coin.

i have calculated the area of both the surfaces.

area =2×πr²=2×π×2.0²=8 π=8×3.14=25.12 cm²

if only one surface then area=π×2²=4π≈12.57 cm²

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Four Questions, 60 points & Brainliest! (Please show all steps)
pogonyaev

Answer:

a) -2, 1 and 2

b) 4

Step-by-step explanation:

The given equation is:

g(x) = (x + 2)(x - 1)(x - 2)

Part a1 and a2) Finding zeros of the function

By zeroes of the function we mean the points the graph where the value of the function is zero. In order to find the zeroes of the function we equate the  function equation to zero and find the corresponding values of x. This is shown below:

0 = (x + 2)(x - 1)(x - 2)

According to the zero product property, we can write:

x + 2 = 0     ⇒     x = -2

x - 1 = 0      ⇒     x = 1

x - 2 = 0     ⇒     x = 2

Therefore, the zeroes of the given function are -2, 1 and 2. In ordered pairs we can write these as (-2, 0), (1, 0) and (2, 0)

Part b1 and b2) y-intercept of the function

y-intercept is the point on the graph where the function crosses the y-axis. Since on y-axis, the value of x coordinate is zero, in order to find the y-intercept we simply substitute zero for all occurrences of x. This is shown below:

g(0) = (0 + 2)(0 - 1)(0 - 2)

g(0) = 2(-1)(-2)

g(0) = 4

Thus, the y-intercept of the function is 4, which in ordered pair can be written as (0, 4)

Part c) End behavior of the graph

End behavior of the graph depends on:

  • Sign of the leading coefficient
  • Degree of the function

Degree of the function is 3 i.e. odd and sign of leading coefficient is positive. This means the end behavior of the graph will be:

  • Rising towards Right end
  • Falling towards Left end

Part d) Graph of polynomial

Based on all the above discussion, a graph of the function can be plotted. The graph is attached below.

4 0
3 years ago
A car and a motorcycle leave the city at the same time and drive to a lake that is 120 km away. The speed of the motorcycle is 2
iris [78.8K]

Answer:

  • 40 km/h and 60 km/h

Step-by-step explanation:

Let the speed of the car is x, then the speed of motorcycle is x + 20

The distance = 120 km

<u>Time:</u>

  • 120/x = 120/(x + 20) + 1
  • 120(x + 20) = 120x + x(x +20)
  • 120x + 2400 = 120x + x² + 20x
  • x² + 20x = 2400
  • x² + 2*10x + 10² = 2500
  • (x + 10)² = 50²
  • x  + 10 = 50
  • x = 40

Speed of the car is 40 km/h

Speed of the motorcycle is 60 km/h

3 0
2 years ago
Read 2 more answers
Help me please I forgot my notes at school
sukhopar [10]
1/2 x 6 = 3
3 x 8 = 24
24/6 = 4
4 - 1 = 3

3 is your answer

hope this helps
6 0
3 years ago
Read 2 more answers
Help plss (find the perimeter) thx
LiRa [457]

Answer:

64 units

Step-by-step explanation:

divide the shape into two shapes:

first one: 15+15+4+4=38

second shape:7+7+6+6=26

pweimwter for the whole shape: 38+26=64 units

3 0
3 years ago
Help me out please!
Marina86 [1]

Answer: Depends on what you come up with . /:

Step-by-step explanation:

3x-11+x+9= if u no the form for this... -x with 3x and -9 -11 should to a division problem so u divide from both sides leaving x = your sum.

4 0
3 years ago
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