Question

if the position vector a of the point (5,n) is such that modulus a is equal to 13 find the value of n

Answer 1

position vector =5i+nj
modulus =√25+n^2=169
n=12

Answer 2

The value of n for the given vector would be n.

1) The position vector A of any point (x,y) is given by xi+yj.

2) Hence, the given vector would be 5i+nj.

3) The modulus of A is $\sqrt{x^2+y^2}$

4) So modulus of the vector would be $\sqrt{5^2 + n^2}$

5) Equating with the equation $\sqrt{25+n^2} = 13$

6) Solving gives n = 12