SOLUTION: Given that cos x= 1/4 with x in Quadrant IV, find the exact value of cos(2x). THANKS!

Question 1070361: Given that cos x= 1/4 with x in Quadrant IV, find the exact value of cos(2x).
THANKS!
Answer by ikleyn(52884) (Show Source): You can put this solution on YOUR website!
.
Given that cos x= 1/4 with x in Quadrant IV, find the exact value of cos(2x).
THANKS!
~~~~~~~~~~~~~~~~~

Use the formula


cos(2x) =  =  =  =  =  = .


The info "with x in Quadrant IV" is excessive, unnecessary and is not used in the solution.


The result, the answer and the solution would be the same even if x in Quadrant I.

RELATED QUESTIONS
suppose sin(x) = 3/5 with x in quadrant I, and cos(y) = 12/13 with y in quadrant IV. find (answered by lwsshak3)

Find the exact value given that sin A = -4/5 with A in quadrant IV, tan B= 7/24 with B in (answered by stanbon)

let cos x = 1/sqrt(10) with x in quadrant IV. find cos... (answered by tommyt3rd)

given sin theta= -root 7/4 and theta is in quadrant IV, find the exact value of cos... (answered by lwsshak3)

Given cos x=4/5, with x being in quadrant IV, find the remaining five trigonometric... (answered by lwsshak3)

find the exact value of the expression using the provided information find sin (A-B)... (answered by stanbon,lwsshak3)

if cos theta = 1/4 in quadrant IV find the exact value of sin( theta -... (answered by lwsshak3)

If cos theta = 1/3, theta in quadrant IV, find the exact value of Tan ( theta +... (answered by lwsshak3)

Find the exact value of sin(a+b), given that sin a=-4/5 and cos b = 12/13, with a in... (answered by ikleyn)