Area under and between curves

The area shown shaded in Figure 125.1 is given by: Figure 125.1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/fig125_1.tif"/> total shaded area = ∫ a b f ( x ) dx − ∫ b c f ( x ) dx + ∫ c d f ( x ) dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4250.tif"/>