sin(x)^2+cos(x)^2 = 1 on different calcs

[Joe Horn]

(09-25-2018 04:22 AM)Gerald H Wrote:  HP 30S returns exactly 1 for input

sin(.1)^2+cos(.1)^2

Indeed, sin(x)^2+cos(x)^2-1 returns 0 for every x I've tried. However:

(09-24-2018 07:09 PM)Dieter Wrote:  If a calculator actually returned 1 exactly in all cases [for sin(x)^2+cos(x)^2] I'd be concerned about its accuracy. ;-)

Dieter is right. Besides, the 30S isn't really an HP calculator. It's a rebranded knockoff of somebody else's calculator. Proof: do 1/3, then Ans×3, then Ans-1. It returns zero, which proves it's cheating by fudging results.