Question
Sin4A - cos4A = sin2A - cos2A
Can i just square root the left side??:O
Can i just square root the left side??:O
Answers
bobpursley
I don't think it is an identity.
let A=90 deg
sin(360)-cos(360)=0-1
sin(180)-cos(180)=0+1
The sides are not equal.
let A=90 deg
sin(360)-cos(360)=0-1
sin(180)-cos(180)=0+1
The sides are not equal.
Kristien
?? Im sorry i don't understand what u did but im sure that this is an identity we have to prove that the left side equals the right side:)