f(x) > 0

a: x^(2) / 4 > 1
d: a
f(x) = x^(3) - 2 * x^(2) - x + 1
c: f(x) > 0
b: f(x) > 0
e: c(x) ∧ d(x)
text1 = LaTeX(c, false)