(sin4x - cos4x)/(sin2x - cos2x)=1, Is this true?
using the formula: a2 - b2 =(a + b)(a - b)
sin4x - cos4x becomes (sin2x + cos2x) (sin2x - cos2x)
we now have
(sin2x + cos2x) (sin2x - cos2x)/(sin2x - cos2x)=1
cancel the following terms
(sin2x + cos2x) (sin2x - cos2x)/(sin2x - cos2x)=1
to get
(sin2x + cos2x)=1