Points On Line of Equation...1

[nycmathguy]

8...(a)

2 = sqrt{5 - 1}

2 = sqrt{4}

2 = 2

I say yes for (a). However, isn't the sqrt{4} a two-fold answer? I thought the sqrt{4} is -2 & 2. No?
Do we disregard -2 because we are talking about a line, which involves distance?

8...(b)

0 = sqrt{5 - 5}

0 = sqrt{0}

0 = 0

I say yes for (b).

Both points lie on the graph of
y = sqrt{5 - x}.

 

[MathLover1]

correct

re:a:
the sqrt{4} is -2 & 2, but question asked if point (1,2) is on the graph

 

[nycmathguy]

correct

re:a:
the sqrt{4} is -2 & 2, but question asked if point (1,2) is on the graph

Understood. The point (1, 2) not (1, -2) is on the graph.