Using an exponential function, it is found that the mass of the radioactive sample at the beginning of the 13th day of the experiment was of 169.1 mg.
<h3>What is an exponential function?</h3>
A decaying exponential function is modeled by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
At the beginning of the first day of the experiment the mass of the substance was 500 grams and mass was decreasing by 8% per day, hence A(0) = 500, r = 0.08, and the equation is given by:



At the 13th day, the mass is given by:

More can be learned about exponential functions at brainly.com/question/25537936
Answer:
solving a quadratic equation by factoring
using the quadratic formula
Step-by-step explanation:
Answer:
The equation in slope-intercept form of the line that crossed the x-axis at 36 and is perpendicular to the line represented by y = -4/9x + 5 is y=9/4x +36
Step-by-step explanation:
Answer:
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Step-by-step explanation:
There was actually too much work for this on my paper so I can't really show it, but if you can memorize this parent function I would.