There is not a formula for everything need more data
Cos(x) = sin(90 - x)
cos(53) = sin(90 - 53)
cos(53) = sin(37)
Answer:
Net Proceeds = Selling Price - Total Cost Price
a. Samantha
Total Cost Price;
Bought shares for d dollars and paid 2% commission = d + (d * 2%) = 1.02d
Selling Price;
Sold stock for s dollars and paid flat fee of $11 = s - 11
Net Proceeds = (s - 11) - 1.02d
b. Alex
Total Cost Price;
Bought x dollars worth and paid 1% commission = x + (x * 1%) = 1.01 * x = 1.01x
Selling Price;
Value falls to y and Alex pays 1.25% when he sells = y - (y * 1.25%) = y - 0.0125y = 0.9875y
Net Proceeds = 0.9875y - 1.01x
