# Wolfram Alpha's Mysterious Trig Abilities [closed]

This is a very straight-forward question:

I'm trying to simplify [sin(2pi*t +pi/4) + sin(2pi*t -pi/4)], and failing at it:

[sin(2pi*t +pi/4) + sin(2pi*t -pi/4)]
[2sin(2pi*t)cos(pi/2)] by sum->product
-20t

sqrt(2)[sin(2pi*t +pi/4) + sin(2pi*t -pi/4)]
sqrt(2)[2sin(2pi*t)cos(pi/4)] by backwards product->sum
-20t (It took me waaay to long to realize the redundancy of this 2nd method... -_-)


Wolfram alpha gives sqrt(2)sin(2pi*t), but gives no explanation as to how. What am I doing wrong?

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## closed as off topic by Szabolcs, ssch, Verbeia♦Feb 27 '13 at 5:30

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Does this question relate to the stand-alone product Mathematica in any way? –  Mr.Wizard Feb 27 '13 at 4:15