Answer:
a = -0.3575
Step-by-step explanation:
The points A and D lie on the x-axis, this means that they are the x-intercepts of the parabola, and therefore we can find their location.
The points A and B are located where

This gives


Now given the coordinates of A, we are in position to find the coordinates of the point B. Point B must have y coordinate of y=2 (because the base of the trapezoid is at y=0), and the x coordinate of B, looking at the figure, must be x coordinate of A plus horizontal distance between A and B, i.e

Thus the coordinates of B are:

Now this point B lies on the parabola, and therefore it must satisfy the equation 
Thus

Therefore


Replace f(x) with y
switch x and y
solve for y
replace y with f⁻¹(x)
f(x)=x-1
y=x-1
x=y-1
x+1=y
x+1=f⁻¹(x)
f⁻¹(x)=x+1
1.30 represents the rate of growth of the mold spores. This decimal is a representation of the percentage growth, which would be 130%.
Since the function is written in terms of weeks, x will equal 4 to represent the amount of spores after 4 weeks. Plug the value into the function:

Rounded to the nearest ones value, there will be 985 mold spores after 4 weeks.
Answer:
1. C. 2. D.
Step-by-step explanation: