SOLUTION: Find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.
cos(u) = −1/7,pi/2<u<pi
Algebra.Com
Question 867571: Find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.
cos(u) = −1/7,pi/2
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.
cos(u) = −1/7,pi/2
***
Interval: [0,3π/2]
cos(u)=-1/7 (In quadrant II)
tan(u)=sin(u)/cos(u)=√48/-1=-√48
...
sin(2u)=2sin(u)cos(u)=2√48/7*(-1/7)=-(2√48)/49
cos(2u)=cos^2(u)-sin^2(u)=1/49-48/49=-47/49
tan(2u)=2tan(u)/1-tan^2(u)=-2√48/(1-48)=2√48/47
..
Calculator check:
cos(u)=-1/7
u≈98.21˚
2u≈196.42˚
...
sin(2u)≈sin(196.42)≈-0.2827…
Exact value=-(2√48)/49≈-0.2827…
..
cos(2u)≈cos(196.42)≈-0.9591…
Exact value=-47/49≈-0.9591…
..
tan(2u)≈tan(196.42)≈-0.2948…
Exact value=-(2√48)/47≈-0.2948…
RELATED QUESTIONS
Find the exact values of sin 2u , Cos 2u, and tan 2u using double angle formulas.
1.... (answered by stanbon)
Find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.
(answered by Boreal,MathTherapy,Alan3354)
Find the exact values of sin 2u,cos 2u, and tan 2u using the double-angle formulas.
tan... (answered by Alan3354)
Find the exact values of
sin 2u,
cos 2u,
and
tan 2u
using the double-angle... (answered by lwsshak3)
Find the exact values of sin(2u), and cos(2u), and tan(2u) using the double angle... (answered by Edwin McCravy)
Find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.
(answered by nyc_function)
find the exact values of sin(2u), cos(2u), and tan(2u) using the double-angle formulas.... (answered by Solver92311)
Find the exact values of sin 2u, cos 2u, and tan 2u using the double-angle formulas.cos u (answered by Alan3354)
Find the exact values of sin(2u),cos(2u),tan(2u)using the half-angle formulas.
sin u =... (answered by greenestamps,ikleyn)