The correct interpretation of the initial value of the function \( f(x) = -75x + 1,200 \) is:
The initial value of 1,200 represents the value of your cell phone at the time you purchase it.
This is because the initial value occurs when \( x = 0 \), which gives \( f(0) = 1,200 \). This signifies the value of the cell phone at the moment of purchase.