Question

cos2theta=√5+1/4 then theta=​

Answer 1

Answer:

cosθ=14 (Given)

eiθ+e−iθ2=14 (#1 and Euler’s formula)

u=eiθ (Define u like this)

u+u−12=14 (Substitute #3 into #2)

u+u−1=12 (Multiply #4 by 2)

u−12+u−1=0 (Subtract 12 from #5)