Step-by-step explanation:
the scaling ratio is 12/20 = 3/5.
this always applies only to one-dimensional distances, lengths.
the perimeter is calculated as the sum of individual lengths. so while each length is scaled by the same ratio, also the sum is then scaled by that ratio.
p_old = a + b + c
p_new = ra + rb + rc = r(a + b + c) = r×p_old
so, the ratio for the perimeter is also 3/5.
for the area this is a bit different, as an area is always calculated by multiplying 2 lengths (other unscaled factors can be ignored for that consideration of relative change), and that means the scaling ratio has to be multiplied in twice.
a_old = a × b
a_new = ra × rb = r² × a×b = r² × a_old
so, the ratio for the area is
(3/5)² = 9/25
Answer:
(a)Yes, it is an exponential function.
(b)
Step-by-step explanation:
(a)A population grows exponentially if it increases by a common ratio(called the growth ratio). We can see from the given information that the population of E.coli doubles every 20 minutes, therefore it is an exponential growth with a growth ratio of 2.
(b)The population, P(t) at any time t of an initial population, 
with a growth ratio of r over a period k can be modeled using the function:
In this Case:
=200
Growth rate,r=2
Growth Period,k=20 minutes
Therefore, the equation that models the function is:
, t is in minutes
This is the associative property of multiplication.
When there are multiple numbers that are only being multiplied, the grouping of such numbers (with parentheses) does NOT matter.
(is/of=%/100)
(12/x= 35/100) = 34.29
(500/400=x/100) = 125
SInce one of the zeros is 1 - 2i, another zero has to be 1 + 2i.
You get a complex zero by taking the square root of a negative number, When you take the square root of a number you get two answers (unless you are taking the square root of zero).
In order to get -2i you had to be taking the sqrt (-4) which is + - 2i
