Answer the Question About the Given Function $f ( x ) = 3 x ^ { 2 } - 6 x + 7$

Multiple Choice

Answer the question about the given function.
-Given the function $f ( x ) = 3 x ^ { 2 } - 6 x + 7$ , what is the domain of $f$ ?

A) all real numbers
B) $\{ x \mid x \geq 1 \}$
C) $\{ x \mid x \leq 1 \}$
D) $\{ x \mid x \geq - 1 \}$