Answer:
Principal amount (P) = $10,000
Rate (R) = 1.5%
Time (T) = 4 years
Simple interest, I = P X R X T / 100
= 10000 X 1.5 X 4 /100
= 60000 / 100
= $600
Therefore, Balance = P + I
= 10000 + 600
= $10600
The total cost before books are printed is $1200 (the constant).
The change to the total cost is the x, which is a variable, and can change depending on the amount of books printed.
hope this helps
Cos Ф - cos Ф.sin² Ф
sin² Ф = 1 - cos² Ф
cos Ф - cos Ф( 1-cos² Ф) = cos Ф - cos Ф - cos³ Ф = cos³ Ф
cos Ф - cos Ф.sin² Ф = cos³ Ф