236 STEP 4. Review the Knowledge You Need to Score High
3.
∫aaf(x)dx= 04.
∫baf(x)dx=−∫abf(x)5.
∫baCf(x)dx=C∫baf(x)dxwhenCis a constant.6.
∫ba[f(x)±g(x)]dx=∫baf(x)dx±∫bag(x)dx7.
∫baf(x)dx≥0 provided f(x)≥0on[a,b].8.
∫baf(x)dx≥∫bag(x)dxprovided f(x)≥g(x)on[a,b].9.
∣
∣∣
∣∫baf(x)dx∣
∣∣
∣≤∫ba∣∣
f(x)∣∣
dx10.
∫bag(x)dx≤∫baf(x)dx≤∫bah(x)dx; providedg(x)≤f(x)≤h(x)on[a,b].- m(b−a)≤
∫baf(x)dx≤M(b−a); providedm≤ f(x)≤Mon [a,b].12.
∫caf(x)dx=∫baf(x)dx+∫cbf(x)dx; providedf(x) is integrable on an interval
containinga,b,c.Examples1.∫ππcosxdx= 02.
∫ 51x^4 dx=−∫ 15x^4 dx3.
∫ 7− 25 x^2 dx= 5∫ 7− 2x^2 dx4.
∫ 40(
x^3 − 2 x+ 1)
dx=∫ 40x^3 dx− 2∫ 40xdx+∫ 401 dx5.
∫ 51√
xdx=∫ 31√
xdx+∫ 53√
xdxNote: Or∫ 31√
xdx=∫ 51√
xdx+∫ 35√
xdx
∫ca=
∫ba+
∫cba, b, cdo not have to be arranged from smallest to largest.