Solve the Equation by Making an Appropriate Substitution $x ^ { 4 } - 14 x ^ { 2 } + 45 = 0$

question 138

Multiple Choice

Solve the equation by making an appropriate substitution.
- $x ^ { 4 } - 14 x ^ { 2 } + 45 = 0$

• A) \(\{ - 3,3 , - \sqrt { 5 } , \sqrt { 5 } \}\)
• B) \(\{ - 3,3 , - \mathrm { i } \sqrt { 5 } , \mathrm { i } \sqrt { 5 } \}\)
• C) \(\{ 9,5 \}\)
• D) \(\{ 3 , \sqrt { 5 } \}\)