SOLUTION: Prove:
Cos^4(x) - Sin^4(x) = 1 - 2Sin^2(x)
Thank you
Algebra.Com
Question 927209: Prove:
Cos^4(x) - Sin^4(x) = 1 - 2Sin^2(x)
Thank you
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Prove:
Cos^4(x) - Sin^4(x) = 1 - 2Sin^2(x)
------
(cos^2)^2 - (sin^2)^2 = 1 - 2sin^2
-------
(1-sin^2)^2 - (sin^2)^2 + 2sin^2 = 1
------
1 - 2sin^2 + sin^4 -sin^4 + 2sin^2 = 1
-----
1 = 1
------
Cheers,
Stan H.
--------------
RELATED QUESTIONS
Prove that... (answered by MathLover1)
Please help prove identity:
{{{2sin(2x)cos(2x)=4cos(x)(sin(x)-2(sin(x))^3)}}}
thank... (answered by eggsarecool)
Prove the identity:
2Sin X • Cos X ÷ (Sin X + Cos X)^2 - 1 = 1
(answered by Shai)
Verify: sin^4 (x)-cos^4... (answered by tommyt3rd)
Verify identity.... (answered by MathLover1)
please help prove:... (answered by Alan3354)
Prove that sin x+ cos x =sqrt(2)sin(x+pi/4)
Please show the steps in detail, thank... (answered by jim_thompson5910)
Good evening,
I'm stuck on this question,
sin(x)cos(x)cos(2x)=(sin(4x))/4
I've been... (answered by jsmallt9)
Prove the identity: {{{sin(2x)/(2sin(x))=cos^2(x/2) -... (answered by Edwin McCravy)