2018 · Q21
The minimum value of the expression 2x² + 5x + 5 is
Elementary MathematicsAlgebra
- A5
- B15/8
- C- 15/8
- D0
Explanation
Completing the square: 2x^2 + 5x + 5 = 2(x + 5/4)^2 + 15/8 >= 15/8. The minimum is attained at x = -5/4 and equals 15/8. The stored key (A) is wrong; the correct value is 15/8. Hence option B.