If \[x=y\cos \frac{2\pi }{3}=z\cos \frac{4\pi }{3}\], then \[xy+yz+zx=\] [EAMCET 1994]

If \[x=y\cos \frac{2\pi }{3}=z\cos \frac{4\pi }{3}\], then \[xy+yz+zx=

1.	If \[x=y\cos \frac{2\pi }{3}=z\cos \frac{4\pi }{3}\], then \[xy+yz+zx=\] [EAMCET 1994]
A.	-1
B.	0
C.	1
D.	2
Answer» C. 1

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If \[x=y\cos \frac{2\pi }{3}=z\cos \frac{4\pi }{3}\], then \[xy+yz+zx=\] [EAMCET 1994]

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