Questions: Quiz 2 (2.3-2.4) - MAC2233 CAI
Quiz 2 (2.3-2.4)
Question 7 of 10
The total sales of a company (in millions of dollars) t months from now are given by the following formula.
S(t)=9 sqrt(t+1)
(A) Use the four-step process to find S'(t).
(B) Find S(15) and S'(15).
(C) Use the results in part (B) to estimate the total sales after 16 months and 17 months.
(A) S'(t)=
(B) S(15)= (Type an integer or a decimal.)
S'(15)= (Type an integer or a decimal.)
(C) S(16) approx (Type an integer or a decimal.)
S(17) approx (Type an integer or a decimal.)
Transcript text: Quiz 2 (2.3-2.4) - MAC2233 CAI
Quiz 2 (2.3-2.4)
Question 7 of 10
The total sales of a company (in millions of dollars) $t$ months from now are given by the following formula.
\[
S(t)=9 \sqrt{t+1}
\]
(A) Use the four-step process to find $\mathrm{S}^{\prime}(\mathrm{t})$.
(B) Find $\mathrm{S}(15)$ and $\mathrm{S}^{\prime}(15)$.
(C) Use the results in part (B) to estimate the total sales after 16 months and 17 months.
(A) $S^{\prime}(t)=$ $\square$
(B) $\mathrm{S}(15)=$ $\square$ (Type an integer or a decimal.)
$S^{\prime}(15)=$ $\square$ (Type an integer or a decimal.)
(C) $\mathrm{S}(16) \approx$ $\square$ (Type an integer or a decimal.)
$\mathrm{S}(17) \approx$ $\square$ (Type an integer or a decimal.)
Solution
Solution Steps
Step 1: Find \( S'(t) \)
To find the derivative \( S'(t) \) of the function \( S(t) = 9 \sqrt{t+1} \), we apply the chain rule. The derivative is given by:
\[
S'(t) = 9 \cdot \frac{1}{2\sqrt{t+1}} = \frac{9}{2\sqrt{t+1}}
\]
Step 2: Calculate \( S(15) \) and \( S'(15) \)
Substituting \( t = 15 \) into the function \( S(t) \):
\[
S(15) = 9 \sqrt{15 + 1} = 9 \sqrt{16} = 36.0
\]
Now, substituting \( t = 15 \) into the derivative:
\[
S'(15) = \frac{9}{2\sqrt{15 + 1}} = \frac{9}{2\sqrt{16}} = \frac{9}{8} = 1.125
\]