operations on vector

Question

If a and b vectors are perpendicular and |a|=5  |b|=12 find |a+b| and |a-b|

 

Answer 1

5² + 12² = c²

 

c = √169 = 13

 

|a+b| = 13

 

5² + (-12)² = c²

 

c = 13

 

|a-b| = 13