When taking square roots, you can't take square roots of negative roots of negative numbers. So, what will work for the domain of u(x) is what makes u(x) zero or more. We can make an inequality for that.
u(x) ≥ 0.
9x + 27 ≥ 0 by squaring both sides
9x ≥ -27
x ≥ -3
So the domain of the function is when x ≥ -3 is true.
Answer: 36 years
Step-by-step explanation:
Exponential equation to represent growth:-
, where A is the initial value , r is the rate of growth and t is the time period.
Given : A rare coin appreciates at a rate of 5.2% a year. If the initial value of the coin is $500.
i.e. Put A= 500 and r= 0.052 in the above formula.
The amount after t years:
Inequality for value cross $3,000 mark:
Divide both sides by 500
Taking log on both sides , we get
Hence, it will take approx 36 years to cross the $3,000 mark.