SOLUTION: Use the given information to find cos 2x, sin 2x, and tan 2x.
cosx=sqrt3/7 and 3π/2 < x < 2π
since I have cos, I created a triangle using sqrt3 as the opposite side.
Algebra.Com
Question 737089: Use the given information to find cos 2x, sin 2x, and tan 2x.
cosx=sqrt3/7 and 3π/2 < x < 2π
since I have cos, I created a triangle using sqrt3 as the opposite side. and 7 as the adjacent side. Then I used the Pythagorean theorem to find the hypotenuse.
hypotenuse^2=(sqrt3)^2+(7)^2
hypotenuse^2=3+49
hypotenuse^2=52
hypotenuse=sqrt52
Then to find sin2x, I used sin2x=2sin(xcos(x), so...
sin2x=2sin(xcos(x)
= 2(sqrt3/sqrt52)(sqrt3/7)
= 2 (sqrt9/7sqrt52)
= 3/7sqrt13
but that was incorrect and I can't go any further in the problem with an incorrect sin2x. Please assist me with where I went wrong or how to go about finding this answer. thanks!
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
cos x =
square both sides
cos^2 x=3/49
1-cos^2 x=1-3/49
sin^2 x = 46/49
cos 2x = 2 cos^2 x -1
=2*3/49-1
=6/49-1
=-43/49
Cos 2x= -43/49
Sin 2x = 2sin x . cos x
=
=
Tan (2x) = sin (2x)/cos (2x)
RELATED QUESTIONS
Use the given information to find cos 2x, sin 2x, and tan 2x. (Enter your answers in... (answered by lwsshak3)
Use the given information to find cos 2x, sin 2x, and tan 2x. (Enter your answers in... (answered by lwsshak3)
Given Tan x= 2/5 with π < x < 3π/2
find sin x/2 cos x/2 tan x/2
sin 2x cos... (answered by lwsshak3)
Use the given information about θ to find the exact values of the following.... (answered by lwsshak3)
I am super confused with this type of questions. I would be grateful for your help.... (answered by Alan3354)
Find sin(2x), cos(2x), and tan(2x) from the given information.
cot(x) = 2/3, x in... (answered by Alan3354)
Is this right? please check exact value of tan(5π/3)sec(-5π/6) and other?... (answered by Alan3354)
sin(x) = 8/17 and π/2 (answered by Alan3354)
Find sin (2x), cos (2x), and tan (2x) from the given information.
tan (x) = 1/2
x... (answered by lwsshak3)