Question

How come f(x)= sqrt(x) considered a function if for example sqrt(9) is both 3 and -3? Why doesn't the graph of swrt(x) include negative numbers?

Answer 1

the mistake is in the line "if for example \(\sqrt9\) is both 3 and -3

Answer 2

\(\sqrt9\) means the positive (principle) square root
9 has two square roots, \(\sqrt9=3\) and \(-\sqrt9=-3\)

Answer 3

no reason, this is a real common mistake

Answer 4

the symbol \(\sqrt{~}\) means the positive one, that is all

Answer 5

Ohhh

Answer 6

It's all about the notation then

Answer 7

yup

Answer 8

Awesome! thanks! ^_^

Answer 9

that is what allows you to have that button on the calculator
it gives the positive one

Answer 10

yw