What is the angle between B and C if A.B = 0 and A x C = 0?

[draotic]

Homework Statement

Given A . B=0 and A x C=0...whats the angle b/w B and C?

Homework Equations

The Attempt at a Solution

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[tiny-tim]

hi draotic!

think! …

if A x C=0...whats the angle b/w A and C? ​

 

[draotic]

ok but wat will be the angle b/w B and C?

 

[tiny-tim]

uh-uh, i asked first! …

whats the angle b/w A and C? ​

 

[draotic]

uh-uh, i asked first! …

whats the angle b/w A and C? ​

must b 180 or 0

 

[tiny-tim]

must b 180 or 0

in other words, A and C are … ?

 

[draotic]

in other words, A and C are … ?

collinear!

 

[tiny-tim]

yup!

so given A . B=0 ...whats the angle b/w B and C?

 

[draotic]

yup!

so given A . B=0 ...whats the angle b/w B and C?

wats it?
i can't think sir

 

[draotic]

yup!

so given A . B=0 ...whats the angle b/w B and C?

thank you sir
its 90 ,right?

 

[HallsofIvy]

You know that A and C are in the same direction (or opposite) so the angle between B and C is the same as the angle between B and A. And you are given that A.B= 0. What does that tell you about the angle between A and B?

 

[tiny-tim]

thank you sir
its 90 ,right?

yes of course!

let's write that out in full, since you don't seem clear on the subject …

A.B = 0, so A is perpendicular to B

but A x C = 0, so A is parallel to C

so C is perpendicular to B ​

oh, and don't call me sir …

i'm only a little goldfish! ​