POW FOR FINANCIAL CALCULATIONS

#!/usr/bin/env python3
"""
POW FOR FINANCIAL CALCULATIONS
Compound interest, investment growth, and time value of money
"""

print("=== Compound Interest Calculator ===")
principal = 1000  # Initial investment
rate = 0.05  # 5% annual interest
years = 10

# A = P(1 + r)^t
final_amount = principal * pow(1 + rate, years)
interest_earned = final_amount - principal

print(f"Principal: ${principal}")
print(f"Rate: {rate*100}% per year")
print(f"Time: {years} years")
print(f"Final amount: ${final_amount:.2f}")
print(f"Interest earned: ${interest_earned:.2f}")

print("\n=== Monthly Compound Interest ===")
principal = 5000
annual_rate = 0.06
years = 5
compounds_per_year = 12

# A = P(1 + r/n)^(nt)
final = principal * pow(1 + annual_rate/compounds_per_year, compounds_per_year * years)
print(f"Starting: ${principal}")
print(f"After {years} years (monthly compounding): ${final:.2f}")
print(f"Total gain: ${final - principal:.2f}")

print("\n=== Investment Doubling Time ===")
# Using rule of 72 verification
rate = 0.08  # 8% return
years_to_double = 9  # 72/8 = 9 years
initial = 10000

final_value = initial * pow(1 + rate, years_to_double)
print(f"Initial investment: ${initial}")
print(f"After {years_to_double} years at {rate*100}%: ${final_value:.2f}")
print(f"Multiple: {final_value/initial:.2f}x")

print("\n=== Depreciation (Negative Growth) ===")
car_value = 30000
depreciation_rate = 0.15  # 15% per year
years = 5

# Value = Initial * (1 - rate)^years
final_value = car_value * pow(1 - depreciation_rate, years)
print(f"Original car value: ${car_value}")
print(f"After {years} years: ${final_value:.2f}")
print(f"Lost value: ${car_value - final_value:.2f}")