Please help me with this question

Asked by akshitaasia | 19th Mar, 2018, 11:04: AM

Expert Answer:

begin mathsize 16px style Let space top enclose straight a equals 2 straight i with hat on top minus straight j with hat on top minus straight k with hat on top space and space straight b with bar on top equals straight i with hat on top plus 2 straight j with hat on top plus straight k with hat on top
Projection space of space top enclose straight a space in space the space direction space of space straight b with bar on top
is space
equals fraction numerator straight a with bar on top times straight b with bar on top over denominator open vertical bar straight b with bar on top close vertical bar end fraction
equals fraction numerator open parentheses 2 straight i with hat on top minus straight j with hat on top minus straight k with hat on top close parentheses times open parentheses straight i with hat on top plus 2 straight j with hat on top plus straight k with hat on top close parentheses over denominator square root of 1 squared plus 2 squared plus 1 to the power of 1 end root end fraction
equals fraction numerator 2 cross times 1 plus open parentheses negative 1 close parentheses cross times 2 plus open parentheses negative 1 close parentheses cross times 1 over denominator square root of 1 plus 4 plus 1 end root end fraction
equals fraction numerator 2 minus 2 minus 1 over denominator square root of 6 end fraction
equals fraction numerator negative 1 over denominator square root of 6 end fraction end style

Answered by Sneha shidid | 19th Mar, 2018, 11:24: AM