Question

What is the axis of symmetry for the function? y = x2 + 3x - 4

y = -2

x = -2

x = -1.5

y = -1.5



What is the vertex for the function? y = x2 - 4x - 3


(-1, 2)

(0, -3)

(1, -6)

(2, -7)



The vertex of y = 9 - 8x - x2 is (-4, 25)

False
True

Answer 1

Axis of symmetry is a line passing through the vertex which divides the curge into two parts such tha each part looks the same.
For
`y= x^(2) +3x-4`, the 'x' part is squared and the coefficient of
`x^(2)` is positive. Hence, the curve will be a parabola facing up which means that the axis of symmetry will be a vertical line. i.e. x = m.
Investigating, f(-1) =
`= (-1)^(2) +3(-1)-4=1-3-4=-6`
f(-1.5) =
`= (-1.5)^(2) +3(-1.5)-4=2.25-4.5-4=-6.25`
f(-2) =
`= (-2)^(2) +3(-2)-4=4-6-4=-6`
From these, the curve has a vertex at point (-1.5, -6)
Therefore the axis of symmetry is line x = -1.5 (i.e. the third option)