To find the axis of symmetry for the given parabola, we start with the standard form of a quadratic equation:
[tex]\[ y = ax^2 + bx + c \][/tex]
Given the equation:
[tex]\[ y = 2x^2 + 4x - 1 \][/tex]
Here, the coefficients are:
- [tex]\( a = 2 \)[/tex]
- [tex]\( b = 4 \)[/tex]
- [tex]\( c = -1 \)[/tex]
The formula to find the axis of symmetry for a parabola in this form is:
[tex]\[ x = -\frac{b}{2a} \][/tex]
Let's substitute the values of [tex]\( a \)[/tex] and [tex]\( b \)[/tex] into the formula:
[tex]\[ x = -\frac{4}{2 \times 2} = -\frac{4}{4} = -1 \][/tex]
Therefore, the axis of symmetry for the given parabola is:
[tex]\[ x = -1 \][/tex]
From the provided answer choices, the correct option is:
b. [tex]\( x = -1 \)[/tex]
So, the best answer is:
B
