One of the main contaminants of a nuclear accident, such as that at chernobyl, is strontium-90, which decays exponentially at a rate of approximately 2.5 % per year. (a) write the ratio of strontium-90 remaining, upper p , as a function of years, t , since the nuclear accident. [hint: 100 % of the contaminant remains at t equals 0, so your function should take on the value 1 at t equals 0.]

we can use formula

we are given

strontium-90, which decays exponentially at a rate of approximately 2.5 % per year

so,

now, we can plug these values

and we  get

..........Answer

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.