Question

Find the vertex f(x)=x2+4x-1

Answer 1

Vertex = (-2, -3)

Explanation:

The vertex of a parabola form

`ax^2+bx+c`

is given by

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

Now, in our case a = 1, and b = 4; therefore, the vertex is

`x=-(4)/(2(1))`
`x=-2`

The x-coordinate of the vertex is x = -2 and now we find the y -coordinate.

The y-coordinate is given by substituting x = -2 into f(x) = x^2 + 4x + 1:

`f(-2)=(-2)^2+4(-2)+1_{}_{}_{}`
`f(-2)=4-8+1`
`f(-2)=-3`

The y-coordinate of the vertex is -3.

Hence, the coorindates of the vertex are x = -2 and x = -3 which can be written as (-2, -3).