Question

if k= 2pi/45 what is the period of y=coskx
a)45/2
b)45
c)45/2pi
d)2pi/45

Answer 1

period of \(\cos(kx)\) is \(\frac{2\pi}{k}\)

Answer 2

\[\frac{2\pi}{\frac{2\pi}{45}}=\frac{2\pi\times 45}{2\pi}=45\]