f = \frac{1}{T}

${f = \frac{1}{T}}$

f = \frac{1}{T}

$f = \frac{1}{T}$

f (1 / s)

$f \;\left(1/s\right)$

T (s)

$T\;\left(s\right)$

T

$T$

s

$s$

1

Lisa