Four times the sum of a number and 15 is at least 120. Let x represent the number. Find all possible values for x.
1 answer:
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Answer:
The domain of is restricted to
, and the domain of
is restricted to
.
Step-by-step explanation:
From Function Theory we know that domain of a function is the set of values such that an image exist. Let and
the function and its inverse, respectively.
At first glance we notice that function is a second order polynomial and every polinomial is a continuous function and therefore, there exists an image for every element of domain.
But domain of its inverse is restricted to every value of x so that , which means that
.
Finally, we concluded that following answer offers the best approximation to our result:
The domain of is restricted to
, and the domain of
is restricted to
.