Pre Calc
posted by John .
How to prove tan4x = 18 sin squared of cos squared of x

I don't think you really meant
tan(4x) = 1  sin^2(cos^2(x)), so do you mean
tan 4x = 1  8 sin^2 x cos^2 x?
Let's see.
8sin^2 x cos^2 x = 2*sin^2(2x))
tan(4x) =? 1  2sin^2(2x)
Naah. Check your problem again.
However, cos(4x) = 1  2sin^2(2x))
Respond to this Question
Similar Questions

calc
Where do I start to prove this identity: sinx/cosx= 1cos2x/sin2x please help!! Hint: Fractions are evil. Get rid of them. Well, cos2x = cos 2 x  sin 2 x, so 1coscx = 1  cos 2 x  sin 2 x = 1  cos 2 x + sin 2 x You should be able … 
Mathematics
I have to show that for any (pi)A, Sin(A)squared + Cos(A)squared = 1. I don't really get the question... am I supposed to multiply A by pi? 
math
How do i find the area of a triangle? For example: A squared + b squared= c squared 8.5 squared + 6.4 squared= c squared 72.25 + 40.96= c squared 113.21=c squared 10.6400188=c even tho i thought this was the answer it is not because 
math
i am having a minor difficulty i've been stuck for over an hour and don't know what to do i don't know is this right ? 
calculus
prove cos squared B sin squared B= 2cos squared B 1 
algebra 2 multiple choice HELP
find f(a), if f(t) = 2t2(squared)t2 A. 2(a+t)2(squared)2t+12 B. 2(t+a)2(squared)2(t+a)2 C. 2a2(squared)a2 D. 4a2(squared)2a2 I put (squared) because the two in front of it means it's being squared... please help. thanks! 
math
prove the identity : cos^4 theta sin ^4 thetaover sin squared theta cos squared theta =cot squared theta  tan squared theta 
Precalculus
Prove or disprove cos(x+y)cos(xy)=cos squared (x)  Sin squared (x) I dstributed the cosines and attempted to cancel out terms but I can't get the signs right. Any help on what I am missing? 
Precalculus with Trigonometry
Prove or disprove the following Identities: cos(x)  sin(x) = cos(x) + sin (x) sin raised to the 4 (theta)  cos raised to the 4 (theta) = sin squared (theta)  cos squared (theta) cos (x+(pi)/(6)) + sin (x  (pi)/(3)) = 0 cos(x+y)cos(xy) … 
Math
Find the shortcut. Solve these problems. Then find and explain a shortcut method for finding the answer. 52(Squared)  42 (squared) = 82 (Squared)  72 (Squared) = 122 (Squared)  112 (Squared) = 312 (Squared)  302 (Squared) = 892 …