$(-\infty,0)$(-\infty,0)

$(0, +\infty)$(0, +\infty)

$\displaystyle \left(-\infty, \frac{3}{4} \right)$\displaystyle \left(-\infty, \frac{3}{4} \right)

$\displaystyle \left( \frac{3}{4}, +\infty \right)$\displaystyle \left( \frac{3}{4}, +\infty \right)