Understanding Square Root Functions
Square root functions contain a radical where the independent variable is inside the radical (the radicand). The parent function for all square root functions is f(x) = √x, which passes through the points (0,0) and (1,1).
When working with square root functions, remember that you can't take the square root of a negative number in the real number system. This means the domain of a square root function is restricted to values where the radicand is non-negative (x ≥ 0).
Let's look at an example y = -4√x. To graph this, create a table of values starting with x = 0, then plot points and connect them with a smooth curve. The negative coefficient (-4) means this function is a vertically stretched and reflected version of the parent function. Its domain is x ≥ 0, and its range is y ≤ 0.
💡 When you see a negative coefficient in front of a square root like−4√x, it means the function is flipped upside down compared to the parent function.