It is the same distance apart. .1875-.125 is .0625
1/4 is .25-.1875 is .0625
A petri dish is simply a circle; thus, we use the formula of the area of the circle which is <span>πr^2.
Given r = 40 mm
A = </span>π(40)^2 = <span>5026.55 sq. mm
</span>
Population density = bacteria count / area
PD = 2,100 / <span>5026.55
PD = </span><span>0.417782 bacteria / mm sq.
Therefore, the answer is approximately 0.418 </span><span>bacteria per square millimeter.</span>
The cosine function with the given characteristics is:
f(x) = 3*cos(x/2 - pi).
<h3>
How to get the cosine function?</h3>
The general cosine function is:
f(x) = A*cos(kx + p)
Where A is the amplitude and p is the phase, then we know that:
A = 3
p = -pi
Then we have:
f(x) = 3*cos(kx - pi)
And the period is equal to 4pi, then we must have that:
k*(x + 4pi) - pi = k*x - pi + 2pi
k = 1/2
Then the function is:
f(x) = 3*cos(x/2 - pi).
If you want to learn more about cosine functions:
brainly.com/question/4372174
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Answer:
? = 7.
Step-by-step explanation:
The two triangles are similar because of the AA Theorem.
The larger triangle's side that is equal to 9 + 3 corresponds to the smaller triangle's side length of 9, while the larger triangle's 21 + ? side corresponds to the smaller triangle's 21 side. Now, we can set up a proportion!
? + 21 = 7 * 4
? + 21 = 28
? = 28 - 21
? = 7
Hope this helps!
