Vector subtraction

In Figure 73.1, a force vector F is represented by oa. The vector (–oa) can be obtained by drawing a vector from o in the opposite sense to oa but having the same magnitude, shown as ob in Figure 73.1, i.e. o b = ( − o a ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq2476.tif"/> Figure 73.1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/fig73_1.tif"/>