The requirement is that every element in the domain must be connected to one - and one only - element in the codomain.
A classic visualization consists of two sets, filled with dots. Each dot in the domain must be the start of an arrow, pointing to a dot in the codomain.
So, the two things can't can't happen is that you don't have any arrow starting from a point in the domain, i.e. the function is not defined for that element, or that multiple arrows start from the same points.
But as long as an arrow start from each element in the domain, you have a function. It may happen that two different arrow point to the same element in the codomain - that's ok, the relation is still a function, but it's not injective; or it can happen that some points in the codomain aren't pointed by any arrow - you still have a function, except it's not surjective.
This can be expressed as exponential growth of the form:
f=ir^t, f=final amount, i=initial amount, r=common ratio (rate), t=time
In this case we are given the point (2, 6500) and i=5000 so we can solve for the rate...
6500=5000r^2 divide both sides by 5000
1.3=r^2 take the square root of both sides and note that we know r>0
r=1.3^(1/2) so our equation becomes:
f=5000(1.3)^(1/2)^t and knowing that (a^b)^c=a^(b*c) we can say:
f=5000(1.3)^(t/2) so for t=18
f=5000(1.3)^9
f≈53022 (to nearest whole bacteria)
First solve for the trig function 'cot'

Next take the sqrt of both sides (include plus/minus)

Now take reciprocal of both sides, this will change trig function to 'tan'
(cot = 1/tan)

Finally use the unit circle or inverse tan on your calculator to find x.
There will be 4 solutions, one for each quadrant.
Answer:
87 feet
Step-by-step explanation:
8 feet below sea level would be -8
95 feet above sea level would be +95
so it would be -8+95
-8+95=87
:)
3+2g=5g-9
5g-2g=3+9
3g=12
3g/3=12/3
g=4