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} }](https://tex.z-dn.net/?f=y%3Dx%28%5Cfrac%7B1%7D%7B2%7D%29%5E%7B%5Cfrac%7Bt%7D%7B22%7D%20%7D)
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