The correct interpretation is:
The initial value of 1,200 represents the value of your cell phone at the time you purchase it.
In the function \( f(x) = -75x + 1,200 \), when \( x = 0 \) (which corresponds to the time of purchase), the value of the cell phone \( f(0) = -75(0) + 1,200 = 1,200 \). This indicates that the cell phone is worth $1,200 at the time of purchase.