# Find a vector the direction of aija¯=i^-2j^ that has magnitude 7 units. - Mathematics and Statistics

Sum

Find a vector the direction of bar"a" = hat"i" - 2hat"j" that has magnitude 7 units.

#### Solution

bar"a" = hat"i" - 2hat"j"

therefore |bar"a"| = sqrt(1^2 + (- 2)^2) = sqrt5

Unit vector in direction of bar"a"

= hat"a" = bar"a"/|bar"a"| = (hat"i" - 2hat"j")/sqrt5

∴ vector of magnitude 7 in the direction of bar"a" is

7hat"a" = 7((hat"i" - 2hat"j")/sqrt5) = 7/sqrt5 hat"i" - 14/sqrt5 hat"j"

Concept: Vectors and Their Types
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