Have you tried the dot product ?
The vectors can form obtuse angle when Dot product is less than Zero...Thats it??
Or is there any other condition??
I get cx^2 - 12 + 6cx < 0,
Then how should i proceed...c value must satisfy for all real x
Thanks in Advance
Sorry for the above thing!!!
i got my answer woo hoo
-4/3 < C < 0 Please verify my Answer