Prove that cos4x=8cos^4x-8cos^2x+1 so I'm

Prove thatcos4x=8cos^4x-8cos^2x+1 so I'm guessing you begin with the left side cos4x=cos2(2x) then im kinda lost
1. 2 answers
2. asked by Natash
3. 1,292 views
Prove:cos4x = 8cos^4x - 8cos^2x + 1 My Attempt: RS: = 4cos^2x (2cos^2x - 1) + 1 = 4 cos^2x (cos2x) + 1 LS: = cos2(2x) =
1. 38 answers
2. asked by Anonymous
3. 2,751 views
Prove that it is an identity: cos (4x)=8cos^4(x)-8cos^2(x)+1
1. 1 answer
2. asked by Anonymus
3. 2,035 views
Show that cos 4 alpha =8cos^4alpha - 8cos^2alpha + 1
1. 1 answer
2. asked by Joshua
3. 135 views
Find all solutions on the interval [0.2pi)A) -3sin(t)=15cos(t)sin(t) I have no clue... b) 8cos^2(t)=3-2cos(t) All i did was move
1. 1 answer
2. asked by Dan
3. 844 views
If x=2cos (z) and y= sin (z), then d^2y/dx^2=?What I got -sin (z) / -8cos (z)*sin (z) simplifies to 1/8cos (z) I don't think I'm
1. 1 answer
2. asked by Liam
3. 453 views
Does anybody know how I can graph these on wolfram? x=cos(8cos(t))sin(t),y=sin(8cos(t))sin(t),z=cos(t).I type as it on
1. 3 answers
2. asked by Anonymous
3. 450 views
Show that Cos 4¤=8cos^4¤ - 8cos^2 + 1
1. 1 answer
2. asked by Azeez
3. 95 views
Why does 1/8cos(2y+6) become 1/8cos(arcsinx/4)?
1. 1 answer
2. asked by Aleks
3. 443 views
Prove the identity.6cos^2(x)-1 -12cos^4(x) +8cos^6(x)= cos^3(2x) Thanks for your help :)
1. 3 answers
2. asked by Tommy
3. 609 views