- #1
TSN79
- 424
- 0
I'm just wondering about something, look at this:
[tex]
\[
\begin{array}{l}
\sqrt {3 + x} + \sqrt {2 - x} = 3 \\
\left( {\sqrt {3 + x} } \right)^2 + \left( {\sqrt {2 - x} } \right)^2 = 3^2 \\
3 + x + 2 - x = 9 \\
5 = 9 \\
\end{array}
\]
[/tex]
Obviously something isn't right here, and I know that if I isolate one of the square roots on the other side, then it all works out. But why doesn't this way work?!
[tex]
\[
\begin{array}{l}
\sqrt {3 + x} + \sqrt {2 - x} = 3 \\
\left( {\sqrt {3 + x} } \right)^2 + \left( {\sqrt {2 - x} } \right)^2 = 3^2 \\
3 + x + 2 - x = 9 \\
5 = 9 \\
\end{array}
\]
[/tex]
Obviously something isn't right here, and I know that if I isolate one of the square roots on the other side, then it all works out. But why doesn't this way work?!