Let's work through each question step-by-step.
Question 1
Given the function \( f(x) = 2x^3 - 3x^2 + 7 \):
-
Calculate \( f(-1) \): \[ f(-1) = 2(-1)^3 - 3(-1)^2 + 7 \] \[ = 2(-1) - 3(1) + 7 \] \[ = -2 - 3 + 7 = 2 \]
-
Calculate \( f(1) \): \[ f(1) = 2(1)^3 - 3(1)^2 + 7 \] \[ = 2(1) - 3(1) + 7 \] \[ = 2 - 3 + 7 = 6 \]
-
Calculate \( f(2) \): \[ f(2) = 2(2)^3 - 3(2)^2 + 7 \] \[ = 2(8) - 3(4) + 7 \] \[ = 16 - 12 + 7 = 11 \]
Final results for Question 1:
- \( f(-1) = 2 \)
- \( f(1) = 6 \)
- \( f(2) = 11 \)
Question 2
Given the function \( f(x) = 12x + 32 \):
Now, check the statements given:
-
\( f(1) = -1 \): \[ f(1) = 12(1) + 32 = 12 + 32 = 44 \quad \text{(False)} \]
-
\( f(0) = 32 \): \[ f(0) = 12(0) + 32 = 0 + 32 = 32 \quad \text{(True)} \]
-
\( f(2) = 1 \): \[ f(2) = 12(2) + 32 = 24 + 32 = 56 \quad \text{(False)} \]
-
\( f(-\frac{1}{2}) = -2 \): \[ f\left(-\frac{1}{2}\right) = 12\left(-\frac{1}{2}\right) + 32 = -6 + 32 = 26 \quad \text{(False)} \]
-
\( f(4) = 72 \): \[ f(4) = 12(4) + 32 = 48 + 32 = 80 \quad \text{(False)} \]
Final results for Question 2:
- The only true statement is \( f(0) = 32 \).
Question 3
Given the function \( p(x) = -2(x - 9)^2 + 100 \):
To find the profit when \( x = 15 \): \[ p(15) = -2(15 - 9)^2 + 100 \] \[ = -2(6)^2 + 100 \] \[ = -2(36) + 100 \] \[ = -72 + 100 = 28 \]
Final result for Question 3:
- The profit when the price of the t-shirts are $15 each is $28.
Summary of Answers
- \( f(-1) = 2 \), \( f(1) = 6 \), \( f(2) = 11 \)
- The true statement is \( f(0) = 32 \)
- Profit from sales if t-shirts are $15 each is $28.