Find the domain of x in the expression. $\sqrt { x ^ { 2 } - 7 x + 12 }$
A) $( - \infty , 3 ] \cup [ 4 , \infty )$
B) $( - \infty , 3 ] \cap [ 4 , \infty )$
C) $( \infty , - 3 ] \cup [ 4 , \infty )$
D) $( \infty , 3 ] \cap [ 4 , \infty )$
E) $( \infty , - 3 ] \cap [ 4 , \infty )$

Question

Find the domain of x in the expression.​ $\sqrt { x ^ { 2 } - 7 x + 12 }$ ​
A) $( - \infty , 3 ] \cup [ 4 , \infty )$
B) $( - \infty , 3 ] \cap [ 4 , \infty )$
C) $( \infty , - 3 ] \cup [ 4 , \infty )$
D) $( \infty , 3 ] \cap [ 4 , \infty )$
E) $( \infty , - 3 ] \cap [ 4 , \infty )$

Quizplus · Accepted Answer

The expression under the square root, $x^2 - 7x + 12$, must be greater than or equal to 0. Factoring the quadratic gives $(x-3)(x-4) \geq 0$, which is true for $x \leq 3$ or $x \geq 4$. Therefore, the domain is $(-\infty, 3] \cup [4, \infty)$.

Find the Domain of X in the Expression x2−7x+12\sqrt { x ^ { 2 } - 7 x + 12 }x2−7x+12​

Find the Domain of X in the Expression $\sqrt { x ^ { 2 } - 7 x + 12 }$