AP EAMCET20228 Jul 2022Evening ShiftMathematicsIndefinite IntegrationActual
3 e^x-7 e^ -x 7 e^x+3 e^ -x d x=K x+L (e^ -2 x + 7 3 )+C then K+L=
Options
- A-3 38
- B21 38
- C38 21
- D-38 3
Correct answer
C. 38 21
Step-by-step solution
aligned I & = 3 e^x-7 e^ -x 7 e^x+3 e^ -x d x & =3 e^x- 7 3 e^ -x 7 e^x+3 e^ -x d x & = 3 7 7 e^x- 49 3 e^ -x 7 e^x+3 e^ -x d x & = 3 7 (7 e^x+3 e^ -x )- 58 3 e^ -x 7 e^x+3 e^ -x d x & = 3 7 d x- 3 7 58 3 e^ -x 7 e^x+3 e^ -x d x aligned I= 3 x 7 - 58 7 e^ -2 x 7+3 e^ -2 x d x Put t=7+3 e^ -2 x d t=-6 e^ -2 x d x aligned & I= 3 x 7 - 58 7 (- 1 6 ) d t t & I= 3 x 7 + 29 21 |t|+C & I= 3 x 7 + 29 21 (7+3 e^ -2 x )+C aligned aligned & K=3 / 7 and L=29 / 21 & K+L= 3 7 + 29 21 = 9+29 21 = 38 21 aligned