Question

A scientist performed an experiment with a radioactive substance whose half-life is 22 min. The scientist will sketch a graph of the situation, where x represents the time since the scientist first measured the substance, and y represents the amount of radioactive substance remaining at that time. The scientist will only sketch the graph in the quadrant or quadrants for which it makes sense to. In which quadrant or quadrants will the scientist sketch the graph?

Answer 1

We are given

x represents the time since the scientist first measured the substance

so, initial quantity =x

y represents the amount of radioactive substance remaining at that time

half-life is 22 min

so, we can write function as

$y=x(\frac{1}{2})^{\frac{t}{22} }$

We can see that this is exponential function

and exponent is over 1/2

and x is initial quantity

and x  can not be negative

so, y also can not be negative

Since, both x and y are positive

so, this function lies on quadrant I...............Answer