SOLUTION: if cos(x)=4/5, find sin(2x)

Question 310476: if cos(x)=4/5, find sin(2x)
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Hint: Use the identities

and

RELATED QUESTIONS
If sin(x)+cos(x) = -1/5, and 3pi/4 ≤ x ≤ pi, find the value of... (answered by Edwin McCravy,ikleyn)

find f'(x) if f(x)=x^2 sin^5 (2x) ----- f'(x) = x^2*[5sin^4(2s)*cos(2x)*2] +... (answered by stanbon)

sin=3\5 cos=4\5 find sin\cos... (answered by fractalier)

if sin x= 4/5, where 0 (answered by edjones)
If sin x = -(4/5) and x is in quadrant IV, find cos (1/2)... (answered by lwsshak3)
If cos(x)=-1/3 where 180 (answered by Collinwilfixyouuprealnice)
If tan(x)=5/4 and sin is less than 0, find cos(x). Thanks (answered by lwsshak3)
If tan x = -1/3 and cos x >0, then.... sin 2x = ? cos 2x = ? tan 2x = ? and (answered by Alan3354)
Find cos(x) if sin(x) =... (answered by Alan3354)