Question

If a and b denote the vectors OA and OB, indicate on the same diagram the vectors OC and OD denoted by a +b and a-b. Draw on another diagram the vector OE denoted by a + 2b.

Answer 1

The three diagrams below show the required

$OC=a+b$

$OD=a-b$

and

$OE=a+2b$