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Vector P=6hati+4sqrt(2)hatj+4sqrt(2)hatk...

Vector `P=6hati+4sqrt(2)hatj+4sqrt(2)hatk` makes angle from Z-axas equal to

A

`cos^(-1)(sqrt(2)/(5))`

B

`cos^(-1)(2sqrt(2))`

C

`cos^(-1)""(2sqrt(2))/(5)`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
C
(c ) `P=6hati+4sqrt(2)hatj+4sqrt(2)hatk`
Let P makes angle `gamma`from Z -axis
`therefore=cos^(-1)((P_(z))/(P))`
`"Here" P_(z)=4sqrt(2)and P+sqrt((6)^(2)+(4sqrt(2))^(2)+(4sqrt(2))^(2))=10`
`gamma= cos ((4sqrt(2))/(10))=cos ^(-1) ((2sqrt(2))/(5))`
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