: ...Is this a bug in Qbasic?<br>
It also shows as .850 in QuickBasic 4.5, VBDOS Pro, VB3 and VB5 Pro. Calc.exe does show .707, though. If it's a bug in QB, then it's apparently a bug in all of Microsoft's basic languages.<br>
: A book that I have on Qbasic says that the command ATN is available. This should mean that if I enter ATN(.4567) for example, the displayed result should be 24.546... (answer in decimal degrees).<br>
You need to convert ATN's output from rads to degrees. <b>* (pi / 180)</b> You can get pi using <b>4 * ATN(1)</b>.<br>
Do you need a specific function to get from Atn to Sin? VB5's help file has a decent sized list (20) of Derived Math Functions dealing with Sin, Cos, Tan and their 1/x functions.