Vector modulus

[c4l3b]

A question from A-level Maths book ... slight problem with j :-

Find a vector of modulus 3 perpendicular to vectors a = i + 2k and b = - i - j - k?

Thanks

 

[Deleted member 4993]

A question from A-level Maths book ... slight problem with j :-

Find a vector of modulus 3 perpendicular to vectors a = i + 2k and b = - j - j - k? << are you sure that is correct??
Thanks

 

[c4l3b]

A question from A-level Maths book ... slight problem with j :-

Find a vector of modulus 3 perpendicular to vectors a = i + 2k and b = - j - j - k? << are you sure that is correct??
Thanks

Just edited the question

 

[Deleted member 4993]

A question from A-level Maths book ... slight problem with j :-

Find a vector of modulus 3 perpendicular to vectors a = i + 2k and b = - i - j - k?

Thanks

first find a vector c - which is perpendicular to both a & b

 

[c4l3b]

To find vector C = a x b then find |a x b|= square-root of 6 ........I understand the principle of modulus but how do i implement it because basically your working with i and k?