Part A
Given f(x) defined below:
[tex]f(x)=-2x^2+8x+1[/tex]
The y-intercept is the value of y when x=0.
[tex]\begin{gathered} f(0)=-2(0)^2+8(0)+1=1 \\ y-\text{intercept:}(0,1) \end{gathered}[/tex]
Vertex
Since the axis of symmetry is given as x=2:
[tex]\begin{gathered} f(2)=-2(2)^2+8(2)+1 \\ =-2(4)+16+1 \\ =9 \\ \implies\text{Vertex:}(2,9) \end{gathered}[/tex]
Minimum/Maximum Value
Since the coefficient of x² is negative, there is a maximum value.
• Maximum Value = 9
,
• The graph opens downwards.
Part B
Given g(x) defined below:
[tex]g(x)=3x^2+6x-4[/tex]
The axis of symmetry is derived using the formula below:
[tex]\begin{gathered} x=-\frac{b}{2a},a=3,b=6 \\ x=-\frac{6}{2\times3}=-\frac{6}{6} \\ x=-1 \end{gathered}[/tex]
• Axis of Symmetry: x=-1
,
• Vertex: (-1,-7)