cos4A=1-8cos^(2)A+8cos^(4)A

Prove that cos 4A=1-8cos^2A+8 cos^4A

Show tha: cos4A=1-8cos^2A+8cos^4A .

cos4 alpha=1-8cos^(2)alpha+8cos^(4)alpha

If sin A+sin^(2)A+sin^(3)A=1, then find the value of cos^(6)A-4cos^(4)A+8cos^(2)A

If sinA+sin^(2)A=1 , then find the value of cos^(12)A+3cos^(10)A+3cos^(8)A+cos^(6)A+cos^(4)A+cos^(2)A .

If sin A + sin^(2)A + sin^(3)A =1 , then , prove that cos^(6) A - 4 cos^(4) A + 8 cos^(2) A =4 .

If sin x+sin^(2)x+sin^(3)x=1 then find the value of cos^(6)x-4cos^(4)x+8cos^(2)x

If theta be any real, prove that : cos4 theta=1-8 sin^2 theta cos^2 theta =1-8 cos^2 theta +8 cos^4 theta .

Prove that: cos^4pi/8+cos^4(3pi)/8+cos^4(5pi)/8+cos^4(7pi)/8=3/2

Prove that: cos^4pi/8+cos^4(3pi)/8+cos^4(5pi)/8+cos^4(7pi)/8=3/2