निम्नाकिंत के बीच का कोण ज्ञात कीजिए -

Explanation

माना `vec a = 2 hati "तथा" vec b = 3hati - 4hatj`
` veca . vec b = (2hati).(3hati - 4 hati)`
`= 6 (hati , hati ) + 0(hatj. hati)+ (hatk. hatk)`
`= 6.1 + 0.1 + 0.1 =6`
`|veca | = |3hati - 4 hatj + 0hatk | = sqrt((3)^(2) + (-4)^(2) + (0)^(2)]) = sqrt(4) = 2`
तथा ` |vec b| = |3hati - 4hatj +0hatk | = sqrt([(3)^(2) + (-4)^(2) + 0])`
` sqrt(25) = 5`
अब , ` cos theta = (vec a . vecb )/(vec|a|.vec|b|)= (6)/(2xx5) = (6)/(10) = (3)/(5)`
` rArr theta = cos^(-1) ((3)/(5))` .