Trigonometer
Geometry
Level
pending
If sin^2(A)=2sinA cosA and sin20=K. Find value of Cos20 Cos40 cos80 cos160
-(sqrt of(1-K^2))
K
-(sqrt of(1-K^2))/8
(sqrt of(1-K^2))/8
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Use these hints, I)Multiply and divide by sin20. II)Use sin^2(A)=2sinA*cosA. III)Lastly sin(180-A)=SinA .