If `a^2+b^2+c^2=20\ \ a n d\ a+b+c=0,` find `a b+b c+c a`

If a^2+b^2+c^2=20 and a+b+c=0 , find a b+b c+c a

If a+b+c=0 and a^2+b^2+c^2=16 , find the value of a b+b c+c a

If a^2+b^2+c^2-a b-b c-c a=0, then (a) a+b=c (b) b+c=a (c) c+a=b (d) a=b=c

If a!=b!=c\ a n d\ |{:(a, b, c), (a^2,b^2,c^2), (b+c, c+a, a+b):}|=0 then a+b+c=0 b. a b+b c+c a=0 c. a^2+b^2+c^2=a b+b c+c a d. a b c=0

If a!=b!=c\ a n d\ |{:(a, b, c), (a^2,b^2,c^2), (b+c, c+a, a+b):}|=0 then a+b+c=0 b. a b+b c+c a=0 c. a^2+b^2+c^2=a b+b c+c a d. a b c=0

If a+b+c=0 and a^2+b^2+c^2=1, then (a) a b+b c+c a=1/2 (b) a b+b c+c a=-1/2 (c) a^4+b^4+c^4=1/2 (d) a^4+b^4+c^4=3/2

In Figure, if /_B A C=60^0\ a n d\ /_B C A=20^0,\ find /_A D C

If a!=b!=c\ and\ |{:(a, b, c), (a^2,b^2,c^2), (b+c, c+a, a+b):}|=0 then A. a+b+c=0 B. a b+b c+c a=0 C. a^2+b^2+c^2=a b+b c+c a D. a b c=0

A B C D is a cyclic quadrilateral in which A C\ a n d\ B D are its diagonals. If /_D B C=55^0\ a n d\ /_B A C=45^0, find /_B C D

If a ,\ b ,\ c ,\ d\ a n d\ p are different real numbers such that: (a^2+b^2+c^2)p^(2)-2(a b+b c+c d)p+(b^2+c^2+d^2)lt=0 , then show that a ,\ b ,\ c and d are in G.P.