Home
Class 12
MATHS
Evaluate int (2x-3)/(x^2-3x+5) dx...

Evaluate `int (2x-3)/(x^2-3x+5) dx`

Text Solution

Verified by Experts

Given `u_(1) = 1, u_(2) = 1,u_(n+2) = u_(n+1) + u_(n) n ge 1`
`u_(n) = 1/(sqrt(5))[((1+sqrt(5))/(2))^(n) - ((1-sqrt(5))/(2))^(n) ]`
`:. u_(2) = (1)/(sqrt(5))[((1+sqrt(5))/(2))^(2)-((1-sqrt(5))/(2))^(2)]`
`= (1)/(sqrt(5))((1+sqrt(5))/(2)+(1-sqrt(5))/(2))((1+sqrt(5))/(2)-(1-sqrt(5))/(2))`
`= (1)/(sqrt(5)) (1 xx sqrt(5)) = 1`
Thus m `u_(n)` is true for `n = 2`
Let it be true for `n = k gt 2`" "(as given `u_(2) = 1`). Then
`u_(k) = (1)/(sqrt(5))[((1+sqrt(5))/(2))^(k) - ((1-sqrt(5))/(2))^(k)]`
Consider that ` u_(k+1) = u_(k) + u_(k-1)` [Using `u_(n+2) = u_(n+1) + u_(n)`] ltbr gt `:. u_(k+1) = 1/(sqrt(5)) [((1+sqrt(5))/(2))^(k) - ((1-sqrt(5))/(2))^(k)]`
`+ (1)/(sqrt(5)) [((1+sqrt(5))/(2))^(k-1)-((1-sqrt(5))/(2))^(k-1)]`
`= (1)/(sqrt(5)) [((1+sqrt(5))/(2))^(k) + ((1+sqrt(5))/(2))^(k-1)]`
`- [((1-sqrt(5))/(2))^(k) + ((1+sqrt(5))/(2))^(k-1)]`
`= 1/(sqrt(5)) [((1+sqrt(5))/(2))^(k-1){(1+sqrt(5))/(2) +1}]`
`- [((1-sqrt(5))/(2))^(k-1){(1-sqrt(5))/(2)+1}]`
`= (1)/(sqrt(5)) [((1+sqrt(5))/(2))^(k-1){(6+2sqrt(5))/(4)}-((1-sqrt(5))/(2))^(k-1){(6-2sqrt(5))/(4)}]`
`= 1/(sqrt(5)) [((1+sqrt(5))/(2))^(k-1)((sqrt(5)+1)/(2))^(2)-((1-sqrt(5))/(2))^(k-1)((sqrt(5)-1)/(2))^(2)]`
`= (1)/(sqrt(5))[((1+sqrt(5))/(2))^(k+1)-((1-sqrt(5))/(2))^(k+1)]`
So, `u_(k+1)` is also true.
Hence, by principle of mathematical induction `u_(n)` is true `AA n gt 1`.
Promotional Banner

Topper's Solved these Questions

  • PRINCIPLE OF MATHEMATICAL INDUCTION

    CENGAGE|Exercise Exercise|9 Videos
  • PERMUTATION AND COMBINATION

    CENGAGE|Exercise Question Bank|4 Videos
  • PROBABILITY

    CENGAGE|Exercise Comprehension|2 Videos

Similar Questions

Explore conceptually related problems

Evaluate int (2x-5)^2 dx

Evaluate int(4x)/(x^(2)-3x+2)dx

Evaluate int (2x^(3)-1)/(x^(4)+x)dx

Evaluate int(3x+5)/(x^2 + 4x+7) dx

Evaluate int(1)/(2x^(2)+3x+5)dx .

Evaluate: int(x^3+1)/(x^2+x)dx

Evaluate int (x^2+8x+3) dx

Evaluate int_(0)^(3)(x^2-6x+5)dx

Evaluate int^6_3 (2x^2+3x+5)dx .

Evaluate int 2x^(3)e^(x^(2))dx .