If `a^2+b^2+c^2=1,t h e na b+b c+c a` lie in the interval `[1/3,2]` b. `[-1,2]` c. `[-1/2,1]` d. `[-1,1/2,]`

If a+b+c=2,a^(2)+b^(2)+c^(2)=1 and abc = 3 then 1/a+1/b+1/c is equal to

If a :(b+c)=1:3 a n d c :(a+b)=5:7, t h e b :(a+c) is equal to 1:2 b. 1:3 c. 2:3 d. 2:1

If a ; b=c : d=e :f=1:2, t h e n (3a+5c+7e):(3b=5d+7f) 1:2 b. 1:4 c. 2:1 d. 8:7

If a+b+c=2,a^(2)+b^(2)+c^(2)=1 and abc=3 then (1)/(a)+(1)/(b)+(1)/(c) is equal to a.1/2 b.2 c.1 d.0

Let a,b,c in R such that a^(2)+b^(2)+c^(2)=2bc,a^(2)+b^(2)+c^(2)!=0 . Then which of the following points lie on the line ax+by+c=0 , is : (A) (-1,2) (B) (1,2) (C) (-1,-2) (D) (2,-1)

If a^(2)+b^(2)+c^(2)-ab-bc-ca=0backslash then |a:b:c is 1:1:2 b.1:1:1 c.1:2:1 d.2:1:1