Question

if resultant of two vectors a and b is √7b.the value of b\a is

Answer 1

Resultant R² = a² + b² + 2ab cos 60°

[sqrt(7) *b]² = a² + b² + ab

7 b² - b² = a² +ab

6 b² - a² = ab

6 (b/a) - (a/b) = 1

6t - 1/t = 1

6 t² -t -1 = 0

(3t+ 1) ( 2t -1) = 0

Hence t = -1/3 or 1/2