Problem
NT-B2-M04-P005 Euler Function
#5
★★☆☆☆ Level 2 of 5
Find \(\varphi(45)\).
Factor \(45=3^2\cdot5\).
Use the formula: \(\varphi(45)=45(1-1/3)(1-1/5)=45\cdot2/3\cdot4/5=24\).
This prevents using Euler with a wrong exponent.