Is there someone show me Why this is not true ?  $$-1=(-1)^1=(-1)^\frac{2}{2}=({(-1)}^{2})^{1/2}=\sqrt{1}=1$$  then :$$-1=1$$  Thank you for any help
I know there must be something unmathematical in the following but I don't know where it is: \begin{align} \sqrt{-1} &amp;= i \\\\\ \frac1{\sqrt{-1}} &amp;= \frac1i \\\\  \frac{\sqrt1}{\sqrt{-1}} &amp;= \frac1i \\\\  \sqrt{\frac1{-1}} &amp;= \frac1i \\\\  \sqrt{\frac{-1}1} &amp;= \frac1i \\\\  \sqrt{-1} &amp;= \frac1i \\\\  i &amp;= \frac1i \\\\  i^2 &amp;= 1 \\\\  -1 &amp;= 1 \quad !!? \end{align}
Reference sObject Fields dynamically from a string value Is it possible to reference the fields of an sObject (opportunity in this example) dynamically from a string value? For example, take the following code:  for(Opportunity o: oppList) {       for(String s : strList) {            // I'd like to set the opportunity field values based on the string             // value that contains the API name of the opportunity field       }  }  So, the variable strList contains the opportunity API field names. I'm trying to clear some fields on the opportunity in a before update trigger, but I have to access the field names dynamically in the strList. I'm looking to take a spontaneous trip for a long weekend. The date is flexible and the destination can be anywhere in the world. Is there a site that would allow me to search airfares within a date range, while keeping the destination parameters open? 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For example, when r = 2, the formula is given by: $\sum_{n=0}^{m}n2^n = 2(m2^m - 2^m +1)$ according to   Thanks! How will the super massive black hole affect our galaxy? I have strange problem. My Wallch icon is huge. See the screenshot:    I removed XFCE settings and reordered items a little. How can I restore normal Wallch icon size?  Update:  My /usr/share/applications/wallch-nautilus.desktop file:  [Desktop Entry] Version=4 Name=Wallch Comment=Change desktop wallpapers automatically Exec=/usr/bin/wallch %U Icon=wallch Terminal=false Type=Application Categories=Utility;Application; MimeType=inode/directory;  Actions=Change_Wallpaper;Start;  [Desktop Action Change_Wallpaper] Name=Change Wallpaper Once Exec=/usr/bin/wallch --change TargetEnvironmet=Unity  [Desktop Action Start] Name=Start/Stop Wallpapers Exec=/usr/bin/wallch --start TargetEnvironment=Unity   And the /usr/share/pixmaps/wallch.png: Heterogeneous vs. inhomogeneous extracting energy from cosmological expansion This question is a more concrete reincarnation of an .  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