Partial derivative is derivative over only 1 variable.
here we have 2 variables so it depends on which variable you want to make partial derivative.
case 1.
df/dx = -3y
case 2
df/dy = 5y^4 - 3x
Answer:
$1340.49
Step-by-step explanation:
From the attached image
Subtotal Cost of Purchased Items

Since the builder receives a 20% contractor's discount, plus and additional 3% for paying in full within 30 days.
Discount = 23% of $1658 = 0.23 X 1658 =$381.34
Total (Less Discount) = 1658-381.34 = $1276.66
Tax on building materials is 5%.
Therefore:
Tax = 5% of $1276.66=0.05 X 1276.66
Tax=$63.83
Therefore, the total bill:
=$1276.66+63.83
Grand Total =$1340.49
Answer:
Step-by-step explanation:
Triangle proportionality theorem,
