Finding Indefinite Integrals Find the indefinite integrals (most general antiderivatives) in Exercises 73-88. You may need to try a solution and then adjust your guess. Check your answers by differentiation. n/(e + 5x-7)ds 74.fe-í+9dt dr 6dr 78 V2) /30 80- dB 10 87. I sinadz ( Hint: sine = 1-cos20 88. cos dx nitial Value Problems Solve the initial value problems in Exercises 89-92 dy dr +1 x2 , y(1)=-1 89. 90.de= (x+) , y(1)-1 Vi 92. arr-cost; r"(0) = r'(0) = 0, r(0) =-1