Question

What are the coordinates of the vertex for the function shown below ?

Answer 1

Answer:

Step-by-step explanation:

We can answer this in two ways:  Differentiation and Graphing.

Differentitate:

The first derivative of a function yields a function that provides the slope for any point on the line of the original function.  The slope of a vertex is zero, so we can set the first derivative to 0 and solve for x.

f(x) = 3(x-1)^2 + 4

f(x) = 3(x-1)(x-1) + 4

f(x) = 3(x^2 - 2x + 1) + 4

f(x) = 3x^2 - 6x + 7

f'(x) = 6x -6

Set this = 0 and find x:

0 = 6x -6

x = 1

The value of y when x=1 in the original equation is:

f(1) = 3(1-1)^2 + 4

y = 4

The vertex is (1,4)

Graph:

You can use DESMOS to plot the function.  The result is attached.  Look for the vertex and read the coordinates.  (1,4) seems to work.