the graph of which function has an axis of symmetry at $x = -\\frac{1}{4}$?\n$f(x)=2x^{2}+x…

the graph of which function has an axis of symmetry at $x = -\\frac{1}{4}$?\n$f(x)=2x^{2}+x - 1$\n$f(x)=2x^{2}-x + 1$\n$f(x)=x^{2}+2x - 1$\n$f(x)=x^{2}-2x + 1$
Answer
Explanation:
Step1: Recall axis - of - symmetry formula
For a quadratic function $f(x)=ax^{2}+bx + c$, the axis of symmetry is given by $x =-\frac{b}{2a}$.
Step2: Check option 1
For $f(x)=2x^{2}+x - 1$, where $a = 2$ and $b = 1$. Then $x=-\frac{b}{2a}=-\frac{1}{2\times2}=-\frac{1}{4}$.
Step3: Check option 2
For $f(x)=2x^{2}-x + 1$, where $a = 2$ and $b=-1$. Then $x =-\frac{b}{2a}=-\frac{-1}{2\times2}=\frac{1}{4}$.
Step4: Check option 3
For $f(x)=x^{2}+2x - 1$, where $a = 1$ and $b = 2$. Then $x=-\frac{b}{2a}=-\frac{2}{2\times1}=-1$.
Step5: Check option 4
For $f(x)=x^{2}-2x + 1$, where $a = 1$ and $b=-2$. Then $x=-\frac{b}{2a}=-\frac{-2}{2\times1}=1$.
Answer:
$f(x)=2x^{2}+x - 1$