Question

if the vector a is perpendicular to b vector what is magnitude of a vector + b vector​

Answer 1

Explanation:

refers to the attachment.......

Answer 2

Answer:

we know that when we find the resultant of two vectors we use either parallelogram law or triangle law of vector addition.

so, when two vectors are perpendicular to each other, (please refer to attachment images)    

the angle between them is 90degree

we also know that cos90=0

now, we have an equation for finding the magnitude of the resultant of two vectors;

$R=\sqrt{a^{2} +b^{2} +2ab cos\beta$   where β is the angle between the two vectors

now since this angle is 90 the equation becomes

$R=\sqrt{a^{2} +b^{2} +2abcos90$  

since cos90 is zero the term 2abcos90 turns out to be zero

so now equation becomes

$R=\sqrt{a^{2} +b^{2}$

thats your answer

hope it helps.........