Home
Class 12
MATHS
If lim(xrarr0)((cotx)(e^(x)-1)-cos^(2)x)...

If `lim_(xrarr0)((cotx)(e^(x)-1)-cos^(2)x)/(sinx)=K,Kepsilonr` then find the value of `[K+11/7]`, where `[.]` represents the greatest integer function.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the limit problem given, we will proceed step by step. ### Step 1: Rewrite the limit We start with the limit expression: \[ \lim_{x \to 0} \frac{(\cot x)(e^x - 1) - \cos^2 x}{\sin x} \] We know that \(\cot x = \frac{\cos x}{\sin x}\). Therefore, we can rewrite the limit as: \[ \lim_{x \to 0} \frac{\frac{\cos x}{\sin x}(e^x - 1) - \cos^2 x}{\sin x} \] ### Step 2: Combine terms Next, we can take a common denominator in the numerator: \[ = \lim_{x \to 0} \frac{\cos x (e^x - 1) - \cos^2 x \sin x}{\sin^2 x} \] ### Step 3: Factor out \(\cos x\) Now, we factor out \(\cos x\) from the numerator: \[ = \lim_{x \to 0} \frac{\cos x \left(e^x - 1 - \cos x \sin x\right)}{\sin^2 x} \] ### Step 4: Expand \(e^x\) and \(\sin x\) Using Taylor series expansions around \(x = 0\): - \(e^x \approx 1 + x + \frac{x^2}{2} + O(x^3)\) - \(\sin x \approx x - \frac{x^3}{6} + O(x^5)\) - \(\cos x \approx 1 - \frac{x^2}{2} + O(x^4)\) Substituting these approximations into the limit: \[ e^x - 1 \approx x + \frac{x^2}{2} \] \[ \cos x \sin x \approx (1 - \frac{x^2}{2})(x - \frac{x^3}{6}) \approx x - \frac{x^3}{6} - \frac{x^3}{2} \approx x - \frac{2x^3}{3} \] ### Step 5: Simplify the expression Now substituting back into the limit: \[ e^x - 1 - \cos x \sin x \approx \left(x + \frac{x^2}{2}\right) - \left(x - \frac{2x^3}{3}\right) = \frac{x^2}{2} + \frac{2x^3}{3} \] Thus, we have: \[ = \lim_{x \to 0} \frac{\cos x \left(\frac{x^2}{2} + \frac{2x^3}{3}\right)}{\sin^2 x} \] ### Step 6: Substitute \(\sin^2 x\) Using \(\sin^2 x \approx x^2\): \[ = \lim_{x \to 0} \frac{\cos x \left(\frac{x^2}{2} + \frac{2x^3}{3}\right)}{x^2} \] ### Step 7: Evaluate the limit Now we can evaluate the limit: \[ = \lim_{x \to 0} \left(\cos x \left(\frac{1}{2} + \frac{2x}{3}\right)\right) \] As \(x \to 0\), \(\cos x \to 1\): \[ = \frac{1}{2} + 0 = \frac{1}{2} \] Thus, we have found that \(K = \frac{1}{2}\). ### Step 8: Find \(K + \frac{11}{7}\) Now we need to calculate: \[ K + \frac{11}{7} = \frac{1}{2} + \frac{11}{7} \] Finding a common denominator (which is 14): \[ = \frac{7}{14} + \frac{22}{14} = \frac{29}{14} \] ### Step 9: Apply the greatest integer function Now we apply the greatest integer function: \[ \left[\frac{29}{14}\right] = 2 \] ### Final Answer Thus, the final answer is: \[ \boxed{2} \]

To solve the limit problem given, we will proceed step by step. ### Step 1: Rewrite the limit We start with the limit expression: \[ \lim_{x \to 0} \frac{(\cot x)(e^x - 1) - \cos^2 x}{\sin x} \] We know that \(\cot x = \frac{\cos x}{\sin x}\). Therefore, we can rewrite the limit as: ...
Promotional Banner

Topper's Solved these Questions

  • TEST PAPERS

    RESONANCE ENGLISH|Exercise Math|105 Videos
  • TEST PAPER

    RESONANCE ENGLISH|Exercise MATHEMATICS|48 Videos
  • TEST SERIES

    RESONANCE ENGLISH|Exercise MATHEMATICS|132 Videos

Similar Questions

Explore conceptually related problems

lim_(xrarr0)((1-cos x)/x^2)

Prove that [lim_(xto0) (sinx)/(x)]=0, where [.] represents the greatest integer function.

lim_(xrarr0)(cos 2x-1)/(cosx-1)

Evaluate : [lim_(x to 0) (sin x)/(x)] , where [*] represents the greatest integer function.

Evaluate : [lim_(x to 0) (tan x)/(x)] , where [*] represents the greatest integer function.

Prove that [lim_(xto0) (tan^(-1)x)/(x)]=0, where [.] represents the greatest integer function.

lim_(xrarr0) (sinx)/(x)= ?

Find x satisfying [tan^(-1)x]+[cos^(-1)x]=2, where [] represents the greatest integer function.

Evaluate: [("lim")_(xto0)(tanx)/x] where [dot] represents the greatest integer function

The value of lim_(xto0)(sin[x])/([x]) (where [.] denotes the greatest integer function) is

RESONANCE ENGLISH-TEST PAPERS-MATHEMATICS
  1. For positive integers K=1,2,3,……….n Let S(k) denotes the area of Delta...

    Text Solution

    |

  2. Number of solutions of the equation sec^(-1)((2)/((1)/(x)+x))+picospix...

    Text Solution

    |

  3. If lim(xrarr0)((cotx)(e^(x)-1)-cos^(2)x)/(sinx)=K,Kepsilonr then find ...

    Text Solution

    |

  4. The derivative of y = (1-x) (2-x)…(n-x) at x= 1 is

    Text Solution

    |

  5. If f(x)=|sinx-|cosx||, then the value of f^(')(x) at x=(7pi)/6 is

    Text Solution

    |

  6. The global maximum value of f(x)=(log)(10)(4x^3-12 x^2+11 x-3),x in [2...

    Text Solution

    |

  7. If 3(a+2c)=4(b+3d), then the equation a x^3+b x^2+c x+d=0 will have no...

    Text Solution

    |

  8. If 3f(cosx)+2f(sinx)=5x, then f^(')(cosx) is equal to (where f^(') den...

    Text Solution

    |

  9. "If "y=x^((x^(x)))," then "(dy)/(dx) is

    Text Solution

    |

  10. If f (x)=(4+x )^(n), n in N and f'(0) represents then r^(th) derivativ...

    Text Solution

    |

  11. Let f(x)=x/(1+x^2) and g(x)=(e^(-x))/(1+[x]) (where [.] denote greates...

    Text Solution

    |

  12. If the derivative of an odd cubic polynomial vanishes at two different...

    Text Solution

    |

  13. f (x)= {{:(3+|x-k|"," , x le k),(a ^(2) -2 + ( sin (x -k))/((x-k))"," ...

    Text Solution

    |

  14. Find the critical (stationary ) points of the function f(X)=(x^(5))/(2...

    Text Solution

    |

  15. If curve y=1-ax^(2) and y=x^(2) intersect orthogonally then a is

    Text Solution

    |

  16. If the relation between subnormal SN and subtangent ST on the curve, b...

    Text Solution

    |

  17. Find the point on the curve y=x^3-11 x+5 at which the tangent is y"...

    Text Solution

    |

  18. Find the equation of tangent to the hyperbola 16x^(2)-25y^(2)=400 perp...

    Text Solution

    |

  19. Find the rate of change of volume of a sphere with respect to its s...

    Text Solution

    |

  20. ((2x+3y)/5)+(2f(x)+3f(y))/5 and f^(')(0)=p and f(0)=q. Then f^(")(0) i...

    Text Solution

    |