Question

Let A= 4i cap + 3j cap and B=3icap + 4jcap .Find the magnitude of Avector +b vector and A-B 

Answer 1

$Vector A + B = (4+3) i + (3+4) j \\ \\ Magnitude of A+B = \sqrt{7^2+7^2} = 7 \sqrt{2} \\ \\ Vector A - B = (4-3) i + (3-4) j = 1 i - 1 j \\ \\ Magnitude of A-B = \sqrt{1^2 + -1^2} = \sqrt2$