JEE Main201911 Jan 2019Evening ShiftMathematicsDefinite IntegrationActual
The integral _ / 6 ^ / 4 d x 2 x ( ⁵ x+ ⁵ x ) equals:
Options
- A1 20 ⁻¹ ( 1 9 3 )
- B1 10 ( 4 - ⁻¹ ( 1 9 3 ) )
- C40
- D1 5 ( 4 - ⁻¹ ( 1 3 3 ) )
Correct answer
B. 1 10 ( 4 - ⁻¹ ( 1 9 3 ) )
Step-by-step solution
I = _ 6 ^ 4 d x 2 x ( ⁵ x+ ⁵ x ) array l = _ 6 ^ 4 ⁵ x ² x 2 x x ( ( ⁵ x )²+1 ) = 1 2 _ 6 ^ 4 ⁴ x ² x ( ⁵ x )²+1 d x array Let ⁴ x=t5 ⁴ x ² x d x=d t When x 4 then t 1 and x 6 then t ( 1 3 )⁵ aligned & I = 1 10 _ ( 1 3 )⁵ ¹ d t t²+1 &= 1 10 ( 4 - ⁻¹ ( 1 9 3 ) ) aligned