Solve the inequality. Write the solution set in interval notation.
-$$- x ^ { 2 } + 8 x - 11

Question

Solve the inequality. Write the solution set in interval notation.
-$$- x ^ { 2 } + 8 x - 11 < 0$$
A) $( - \infty , 4 - \sqrt { 5 } ) \cup ( 4 + \sqrt { 5 } , \infty )$
B) $( - 4 - \sqrt { 5 } , - 4 + \sqrt { 5 } )$
C) $( 4 - \sqrt { 5 } , 4 + \sqrt { 5 } )$
D) $( - \infty , - 4 - \sqrt { 5 } ) \cup ( - 4 + \sqrt { 5 } , \infty )$

Quizplus · Accepted Answer

The inequality is a quadratic inequality. The solution set is the union of the two intervals where the quadratic is negative. The quadratic is negative when $x < 4 - \sqrt { 5 } $ or $x > 4 + \sqrt { 5 } $. So the solution set is $( - \infty , 4 - \sqrt { 5 } ) \cup ( 4 + \sqrt { 5 } , \infty )$.

Solve the Inequality −x2+8x−11<0- x ^ { 2 } + 8 x - 11 < 0−x2+8x−11<0

Solve the Inequality $- x ^ { 2 } + 8 x - 11 < 0$