Chapter 4 - Integration - 4.3 Integration By Substitution - Exercises Set 4.3 - Page 286: 1

a. $(x^2 + 1)^{24}/24 + C$ b. $−(cos^{4}x)/4 + C$

a. Considering u=($x^{2}+1$) therefore $du=2x dx$ So by substituting, we get, $\int u^{23}du = u^{24}/24 + C$ b. Considering $u=cosx$ therefore $du=-sinx dx$ So by substituting, we get, $−\int u^3du = −u^4/4 + C$