Question

What is the line of symmetry for the parabola whose equation is y = -x2 + x + 3?

x = -1
x = -1/2
x = 1/2

Answer 1

1/2 is correct, the formula to use is x= - b/2a :)

Answer 2

`x = (1)/(2)`

Explanation:

Given

`y = -x^2 + x + 3`

Required

The line of symmetry

This is calculated using:

`x= -(b)/(2a)`

Where:

`y = ax^2 + bx + c`

So, by comparison:

`a = -1`
`b = 1`
`c = 3`

So, we have:

`x = -(1)/(2 * -1)`

`x = -(1)/(-2)`

`x = (1)/(2)`