Question

Identify the vertex, axis of symmetry, minimum or maximum, domain, and range of the function f(

Answer 1

Identify the vertex, axis of symmetry, minimum or maximum, domain, and range of the function ()=−(+)^−

Answer:

vertex = (-4, -5)

Axis of symmetry = -4

use the (-4, -5) to find the minimum value

$Domain = ( - \infty, \infty ) , [ x | x\ is\ real ]\\\\Range = [ -5, \infty ), y\geq -5$

Solution:

Given function is:

$f(x) = (x+4)^2 - 5$

The equation in vertex form is given as:

$y = a(x-h)^2+k$

Where, (h, k) is constant

On comparing give function with vertex form,

h = -4

k = -5

Vertex is (-4 , -5)

Axis of symmetry : x co-ordinate of vertex

Thus, axis of symmetry = -4

The coefficient of x^2 is positive in given function.

Thus the vertex point will be a minimum

$Minimum\ value = f(\frac{-b}{a})$

$f(x) = x^2 + 8x + 16 - 5\\\\f(x) = x^2 + 8x + 11$

$f(x) = ax^2+bx+c$

On comparing,

a = 1

b = 8

$x = \frac{-b}{2a} = \frac{-8}{2 \times 1} = -4$

$f(-4) = (-4)^2 + 8(-4) + 11 = 16 - 32 + 11 = -5$

Thus, use the (-4, -5) to find the minimum value

Domain and range

$f(x) = (x+4)^2 - 5$

The domain is the input values shown on the x-axis

The range is the set of possible output values f(x)

Therefore,

$Domain = ( - \infty, \infty ) , [ x | x\ is\ real ]\\\\Range = [ -5, \infty ), y\geq -5$