Question 196708
{{{(x-4)(x-4) = 10}}} Perform the indicated multiplication.
{{{x^2-8x+16 = 10}}} Now subtract 10 from both sides.
{{{x^2-8x+6 = 0}}} Write this equation as a function.
{{{f(x) = x^2-8x+6}}}
Ask the question: "For each value of x, do you get a unique value of f(x)?"
The answer here is yes, so it is is a function.
Another way to determine if it is a function is called the "vertical line test".
Graph the function and draw a vertical line through the curve. If the verical line intersects the curve in only one place, then it is a function.
{{{graph(400,400,-5,10,-12,5,x^2-8x+6)}}}
This is also true, so it is a function.