Is it bug? CAS solve function.

[Carsen]

You can also use the EXACT command to convert your equations from approximate to exact. Here I used within the solve command in the CAS environment (see one of the pictures below. The equation is outlined in red). You get the exact answers of 1 and 0 in this case.

You can also use the Solve APP to get the answers (In two more pictures below). This solver only uses approximate answers so your 0 will just be a really small number. Extremely useful APP.