Answer:
Sarah can have the plumber work on her faucet for six (6) hours maximum
Step-by-step explanation:
Hi
As Sarah has only $234.50 in her savings and the plumber charges $50 just to come to her home, so left-over $184.50 of her saving for pay work hours.
Then as the plumber charges $30.75 per hour we have that is the maximum amount of hours that Sarah can have the plumber work on her faucet.
Using derivatives, it is found that the x-values in which the slope belong to the interval (-1,1) are in the following interval:
(-15,-10).
<h3>What is the slope of the tangent line to a function f(x) at point x = x0?</h3>It is given by the derivative at x = x0, that is:
.
In this problem, the function is:
Hence the derivative is:
For a slope of -1, we have that:
0.4x + 5 = -1
0.4x = -6
x = -15.
For a slope of 1, we have that:
0.4x + 5 = 1.
0.4x = -4
x = -10
Hence the interval is:
(-15,-10).
More can be learned about derivatives and tangent lines at brainly.com/question/8174665
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