Question

The ratio of maximum and minimum magnitudes of the resultant of two vectors a and b is 3:1.
Then find magnitude of a in terms of b.

Answer 1

Answer:

a=4/b

Explanation:

magnitude of vector A and B is $\sqrt{a^{2}+b^{2}+2abcos }$Ф.Max value is$\sqrt{a^{2} +b^{2} +2ab$ which equals 3units and min value is $\sqrt{a^{2} +b^{2}$ which is 1 unit.

Squaring on both sides

$a^2+b^2+2ab=9$

$a^2+b^2=1$

2ab=8

ab=4

a=4/b

Answer 2

Answer: 2b

Explanation:

a+b/a-b = 3/1

3a-3b = a+b

2a=4b

a = 2b