Homework Statement
determine A and φ: f(x)=Acos(2t+φ)=4cos(2t+1/4π)+5sin(2t)
Homework Equations
the answer has to be in the form of Aeφi
The Attempt at a Solution
for working towards the answer, the tekst states:
α1=4e1/4πi=2√2+2√2i
and
α2=5e-1/2πi=-5i
I fail to see how they get 5e-1/2πi...