<span>Let's use the quadratic formula:
2w² -</span><span><span> 20w </span>+ 50 = 0</span>
a = 2 b = -20 c = 50
x = -b +-sq root(b^2 - 4*a*c) / 2*a
x = --20 +-sq root(400 -4*2*50) / 4
x = 20 +-sq root(400 -4*2*50) / 4
x = 20 +-sq root( 0) / 4
x = 20 / 4 =5
I'd say it has one rational solution.
It does NOT have 2 solutions because the "plus / minus" section = 0.
Question 4
<h3>Answer: Choice D) 0 <= x <= 30, -3</h3>
The domain is the set of allowed x inputs of a function. The smallest x can be in this case is x = 0. The largest is x = 30. So 0 <= x <= 30 is our domain here.
Calculate the slope of the line through (0,90) and (30,0) to find the average rate of change over the entire domain
m = (y2-y1)/(x2-x1)
m = (0-90)/(30-0)
m = -90/30
m = -3
The average rate of change over the entire domain is -3. This means the population is decreasing by 3 bacteria per minute on average if we consider the entire domain (basically the entire lifetime of the bacteria sample).
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Question 13
<h3>Answer: Choice C) original populations are equal for both states</h3>
To show why this answer works, plug x = 0 into the f(x) function
f(x) = 2*(1.08)^x
f(0) = 2*(1.08)^0
f(0) = 2
The initial population of state A is 2 million people.
State B also starts with 2 million people because of the y intercept (0,2), which is where the graph crosses through the vertical y axis number line.
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Question 15
<h3>Answer: Choice A) exponential increases faster</h3>
The exponential may start off slowly, but over time the exponential growth rate ramps up and the growth rate gets faster and faster (ie accelerates more). The linear function will grow at the same rate no matter what.
V = PI x r^2 x H
V = 3.14 x 4^2 x 20 = 1004.8 cubic meters
1004.8 x 0.60 = 602.88 cubic meters
100,002 divded by 13 will be 7692 when estimated
