Home
Class 12
MATHS
If n is a positive integer then 2^(n)gt1...

If n is a positive integer then `2^(n)gt1+nsqrt((2^(n-1)))`. True or False.

Text Solution

AI Generated Solution

The correct Answer is:
To determine whether the statement \(2^n > 1 + n\sqrt{2^{n-1}}\) is true or false for positive integers \(n\), we will analyze and simplify the inequality step by step. ### Step 1: Rewrite the Inequality We start with the inequality: \[ 2^n > 1 + n\sqrt{2^{n-1}} \] We can rewrite \(\sqrt{2^{n-1}}\) as \(2^{(n-1)/2}\). Thus, the inequality becomes: \[ 2^n > 1 + n \cdot 2^{(n-1)/2} \] ### Step 2: Isolate Terms Next, we can isolate \(2^n\) on one side: \[ 2^n - n \cdot 2^{(n-1)/2} > 1 \] ### Step 3: Factor Out Common Terms Notice that \(2^n\) can be expressed as \(2^{(n-1)/2} \cdot 2^{(n+1)/2}\). Therefore, we can factor out \(2^{(n-1)/2}\): \[ 2^{(n-1)/2}(2^{(n+1)/2} - n) > 1 \] ### Step 4: Analyze the Factor Now we need to analyze the term \(2^{(n+1)/2} - n\). For \(n = 1\): \[ 2^{(1+1)/2} - 1 = 2^{1} - 1 = 1 > 0 \] For \(n = 2\): \[ 2^{(2+1)/2} - 2 = 2^{3/2} - 2 \approx 2.828 - 2 = 0.828 > 0 \] For \(n = 3\): \[ 2^{(3+1)/2} - 3 = 2^{2} - 3 = 4 - 3 = 1 > 0 \] For \(n = 4\): \[ 2^{(4+1)/2} - 4 = 2^{5/2} - 4 = 4\sqrt{2} - 4 \approx 5.656 - 4 = 1.656 > 0 \] As we can see, for small values of \(n\), \(2^{(n+1)/2} - n\) remains positive. ### Step 5: General Case for Larger \(n\) As \(n\) increases, \(2^{(n+1)/2}\) grows exponentially while \(n\) grows linearly. Thus, for sufficiently large \(n\), \(2^{(n+1)/2} - n > 0\) will hold true. ### Conclusion Since we have shown that \(2^{(n+1)/2} - n > 0\) for small values of \(n\) and it continues to hold true as \(n\) increases, we conclude that: \[ 2^n > 1 + n\sqrt{2^{n-1}} \] is true for all positive integers \(n\). ### Final Answer **True**
Promotional Banner

Topper's Solved these Questions

  • INEQUALITIES

    ML KHANNA|Exercise PROBLEM SET (1)(FILL IN THE BLANKS)|4 Videos
  • INEQUALITIES

    ML KHANNA|Exercise PROBLEM SET (1)(FILL IN THE BLANKS)|4 Videos
  • HEIGHTS AND DISTANCES

    ML KHANNA|Exercise Problem Set (3) FILL IN THE BLANKS|9 Videos
  • INTEGRATION

    ML KHANNA|Exercise SELF ASSESSMENT TESET|10 Videos

Similar Questions

Explore conceptually related problems

If n is a positive integer,then nC_(1)+nC_(2)+...+nC_(n)=2^(n)-1

If 'n' is a positive integer,then n.1+(n-1).2+(n-2).3+...+1.n=

If n is a positive integer, then 2.4^(2n + 1) + 3^(3n+1) is divisible by :

If n is a positive integer,then (1+i)^(n)+(1-1)^(n) is equal to

If n is a positive integer,then (sqrt(3)+1)^(2n)-(sqrt(3)-1)^(2n) is (1) an irrational number (2) an odd positive integer (3) an even positive integer (4) a a rational number other than positive integers

If n is any positive integer,write the value of (i^(4n+1)-i^(4n-1))/(2)

Assertion: If n is an even positive integer n then sum_(r=0)^n ^nC_r/(r+1) = (2^(n+1)-1)/(n+1) , Reason : sum_(r=0)^n ^nC_r/(r+1) x^r = ((1+x)^(n+1)-1)/(n+1) (A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true R is not te correct explanation of A (C) A is true but R is false. (D) A is false but R is true.

ML KHANNA-INEQUALITIES-PROBLEM SET (1)(TRUE AND FALSE)
  1. If a>0,b>0,c>0 prove that a/(b+c)+b/(c+a)+c/(a+b)ge3/2.

    Text Solution

    |

  2. If n is a positive integer then 2^(n)gt1+nsqrt((2^(n-1))). True or Fal...

    Text Solution

    |

  3. If a,b,c are in HP, then prove that (a+b)/(2a-b)+(c+b)/(2c-b)gt4.

    Text Solution

    |

  4. If a > ba n dn is a positive integer, then prove that a^n-b^n > n(a b)...

    Text Solution

    |

  5. If agtbgt1 then a^(n)-b^(n)gtn(a-b) for every +ive integer n ge2.True ...

    Text Solution

    |

  6. 2/(b+c)+2/(c+a)+2/(a+b)gt9/(a+b+c)

    Text Solution

    |

  7. If S=a+b+c then prove that (S)/(S-a)+(S)/(S-b)+(S)/(S-c) gt (9)/(2) wh...

    Text Solution

    |

  8. 3/(b+c+d)+3/(c+d+a)+3/(d+a+b)+3/(a+b+c)gt16/(a+b+c+d)

    Text Solution

    |

  9. n(n+1)^(3)lt8(1^(3)+2^(3)+3^(3)+………+n^(3))

    Text Solution

    |

  10. If a, b, c are in H.P. and they are distinct and positive then prove t...

    Text Solution

    |

  11. Sum of the nth powers of the m^(th) power of n even numbers is gtn(n+1...

    Text Solution

    |

  12. If a,b,c are real numbers such that a^(2)+b^(2)+c^(2)=1 then ab+bc+cag...

    Text Solution

    |

  13. In any triangle the semi perimeter is greater than each of its sides.

    Text Solution

    |

  14. The sum of the cubes of the legs of a right angled triangle is less th...

    Text Solution

    |

  15. Thesum of the hypotenuse and the altitude of a right angled triangle d...

    Text Solution

    |

  16. The area of an arbitrary triangle is less than one fourth the square o...

    Text Solution

    |

  17. If x,y,z are all positive and x lt y lt z, then (x^(2))/zlt(x^(2)+y^(2...

    Text Solution

    |

  18. If 0ltalpha(1)ltalpha(2)lt……….ltalpha(n)lt(pi)/2 then tan alpha(1)lt...

    Text Solution

    |

  19. If A+B+C=pithen "tan"^(2)A/2+"tan"^(2)B/2+"tan"^(2)C/2ge1.

    Text Solution

    |

  20. Prove that 2sinx + tanx ge3x, for all x in [0, pi/2].

    Text Solution

    |