Hello!
We can solve for the vertex by completing the square. Begin by factoring out 6 from the equation to simplify the process:
6(x² - 8x) - 54 = 0
To complete the square, we must look at the first two terms (x² - 8x).
Remember that squaring a binomial uses the format a² + 2ab + b². We are already given a² and 2ab², so solve for b:
-8 / 2 = -4. This is the value of b.
We can rewrite this as:
(x - 4)²
However, this produces +16 which much be taken into account. Substitute (x - 4)² into the original equation:
6(x - 4)² - 54 = 0
Multiply 16 by the term in the front and subtract to cancel out this term:
6(x - 4)² - 54 - (6 · 16) = 0
Simplify:
6(x - 4)² - 150 = 0
In this form, the vertex is given as:
a(x - h)² + k, where h = x-coordinate and k = y-coordinate of the vertex.
In this instance, h = 4 and k = -150, so the coordinates of the vertex are:
(4, -150)
keeping in mind that a function does not have any X-Repeats, that is, the 1st coordinate in every pair never repeats, well, in this case, all of them have no X-repeats, that means all of them are functions. However, only one-to-one functions have an inverse that is also a function.
A one-to-one function is one that has no X-repeats as well as no Y-repeats, so each pair in the set has no coordinate repeats, Check the picture below.
