AP EAMCET20225 Jul 2022Morning ShiftMathematicsIndefinite IntegrationActual
If I_n= ( ^n x+ ^n x ) d x and I_n- n-1 n I_ n-2 = x x n f(x) , then f(x)=
Options
- A^ n-2 x+ ^ n-2 x
- B^ n-2 x- ^ n-2 x
- C^ n-2 x- ^ n-2 x n
- D^ n-2 x+ ^ n-2 x n
Correct answer
B. ^ n-2 x- ^ n-2 x
Step-by-step solution
Here, I_n= ( ^n x+ ^n x ) d xI_n= ^ n-1 x x d x+ ^ n-1 x x d x Using by parts, aligned I_n & .= ^ n-1 x x d x- ( d d x ( ^ n-1 x ) x d x ) ) d x & + ^ n-1 x x d x- ( d d x ( ^ n-1 ) ( d x ) d x . aligned aligned I_n & = ^ n-1 x+ (n-1) ^ n-2 x ^2 x d x & - ^ n-1 x x+ (n-1) ^ n-2 x ^2 x d x aligned array rl I_n= ^ n-1 x x- ^ n-1 & x x + & (n-1) I_ n-2 -(n-1) I_n array aligned I_n(1+n-1)-( & (n-1) I_ n-2 & = ^ n-1 x x- ^ n-1 x x aligned aligned & n (l_n )-(n-1) I_ n-2 = ^ n-1 x x- ^ n-1 x x & I_n- ( n-1 n ) I_ n-2 = x