Home
Class 9
MATHS
If m = (1)/(3-2sqrt(2)) and n = (1)/(3+...

If m `= (1)/(3-2sqrt(2))` and `n = (1)/(3+2sqrt(2))` find :
(i) `m^(2)` (ii) `n^(2)` (iii) mn

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find \( m^2 \), \( n^2 \), and \( mn \) given: \[ m = \frac{1}{3 - 2\sqrt{2}} \quad \text{and} \quad n = \frac{1}{3 + 2\sqrt{2}} \] ### Step 1: Rationalizing \( m \) To rationalize \( m \), we multiply the numerator and denominator by the conjugate of the denominator, which is \( 3 + 2\sqrt{2} \): \[ m = \frac{1}{3 - 2\sqrt{2}} \cdot \frac{3 + 2\sqrt{2}}{3 + 2\sqrt{2}} = \frac{3 + 2\sqrt{2}}{(3 - 2\sqrt{2})(3 + 2\sqrt{2})} \] Calculating the denominator using the difference of squares: \[ (3 - 2\sqrt{2})(3 + 2\sqrt{2}) = 3^2 - (2\sqrt{2})^2 = 9 - 8 = 1 \] Thus, we have: \[ m = 3 + 2\sqrt{2} \] ### Step 2: Rationalizing \( n \) Next, we rationalize \( n \) in a similar manner by multiplying by the conjugate \( 3 - 2\sqrt{2} \): \[ n = \frac{1}{3 + 2\sqrt{2}} \cdot \frac{3 - 2\sqrt{2}}{3 - 2\sqrt{2}} = \frac{3 - 2\sqrt{2}}{(3 + 2\sqrt{2})(3 - 2\sqrt{2})} \] Calculating the denominator: \[ (3 + 2\sqrt{2})(3 - 2\sqrt{2}) = 3^2 - (2\sqrt{2})^2 = 9 - 8 = 1 \] Thus, we have: \[ n = 3 - 2\sqrt{2} \] ### Step 3: Finding \( m^2 \) Now, we calculate \( m^2 \): \[ m^2 = (3 + 2\sqrt{2})^2 \] Using the formula \( (a + b)^2 = a^2 + 2ab + b^2 \): \[ = 3^2 + 2 \cdot 3 \cdot 2\sqrt{2} + (2\sqrt{2})^2 = 9 + 12\sqrt{2} + 8 = 17 + 12\sqrt{2} \] ### Step 4: Finding \( n^2 \) Now, we calculate \( n^2 \): \[ n^2 = (3 - 2\sqrt{2})^2 \] Using the same formula: \[ = 3^2 - 2 \cdot 3 \cdot 2\sqrt{2} + (2\sqrt{2})^2 = 9 - 12\sqrt{2} + 8 = 17 - 12\sqrt{2} \] ### Step 5: Finding \( mn \) Now we calculate \( mn \): \[ mn = (3 + 2\sqrt{2})(3 - 2\sqrt{2}) \] Using the difference of squares: \[ = 3^2 - (2\sqrt{2})^2 = 9 - 8 = 1 \] ### Final Results Thus, the final results are: (i) \( m^2 = 17 + 12\sqrt{2} \) (ii) \( n^2 = 17 - 12\sqrt{2} \) (iii) \( mn = 1 \)
Promotional Banner

Topper's Solved these Questions

  • RATIONAL AND IRRATIONAL NUMBERS

    ICSE|Exercise EXERCISE 1 (D)|21 Videos
  • RATIONAL AND IRRATIONAL NUMBERS

    ICSE|Exercise EXERCISE 1 (B)|43 Videos
  • PYTHAGORAS THEOREM

    ICSE|Exercise 4 MARKS QUESTIONS|9 Videos
  • RECTILINEAR FIGURES

    ICSE|Exercise QUADRILATERALS AND ITS PROPERTIES - 4 MARKS QUESTIONS|7 Videos

Similar Questions

Explore conceptually related problems

If l : m = 2 (1)/(2) : 1(2)/(3) and m : n = 1 (1)/(4) : 3 (1)/(2) , find l : m : n

If (m + n)/(m + 3n) = (2)/(3) , find : (2n^(2))/(3m^(2) + mn) .

If x=2sqrt(3)+2sqrt(2) , find : (i) 1/x" (ii) "x+1/x" (iii) "(x+1/x)^(2)

If m = root(3)(15) and n = root(3)(14) , find the value of m - n - (1)/(m^(2) + mn + n^(2))

Find the square of : (iii) 2m^(2) - (2)/(3) n^2

Evaluate : (i)sqrt(3-2sqrt(2))" "(ii)sqrt(9+6sqrt(2))

Find (m+n)-:(m-n) , if : (i) m=(2)/(3) "and" n=(3)/(2) (ii) m=(3)/(4) "and" n=(4)/(3) (iii) m=(4)/(5) "and" n=-(3)/(10)

If m=root3(125) and n=root3(64) , find the value of m-n-(1)/(m^(2)+mn+n^(2)) .

Sum of 1/(sqrt(2)+sqrt(5))+1/(sqrt(5)+sqrt(8))+1/(sqrt(8)+sqrt(11))+1/(sqrt(11)+sqrt(14))+..to n terms= (A) n/(sqrt(3n+2)-sqrt(2)) (B) 1/3 (sqrt(2)-sqrt(3n+2) (C) n/(sqrt(3n+2)+sqrt(2)) (D) none of these

If log_(2)m=sqrt(7)andlog_(7)n=sqrt(2) ,mn=

ICSE-RATIONAL AND IRRATIONAL NUMBERS -EXERCISE 1 (C)
  1. Find the values of a and b in each of the (5+3sqrt(2))/(5-3sqrt(2)...

    Text Solution

    |

  2. Simplify : (22)/(2sqrt(3)+1)+(17)/(2sqrt(3)-1)

    Text Solution

    |

  3. Simplify : (sqrt(2))/(sqrt(6)-sqrt(2))- (sqrt(3))/(sqrt(6)+sqrt(2))

    Text Solution

    |

  4. If x =(sqrt(5)-2)/(sqrt(5)+2) and y = (sqrt(5)+2)/(sqrt(5)-2) : find :...

    Text Solution

    |

  5. If x =(sqrt(5)-2)/(sqrt(5)+2) and y = (sqrt(5)+2)/(sqrt(5)-2) : find :...

    Text Solution

    |

  6. If x =(sqrt(5)-2)/(sqrt(5)+2) and y = (sqrt(5)+2)/(sqrt(5)-2) : find :...

    Text Solution

    |

  7. If x =(sqrt(5)-2)/(sqrt(5)+2) and y = (sqrt(5)+2)/(sqrt(5)-2) : find :...

    Text Solution

    |

  8. If m = (1)/(3-2sqrt(2)) and n = (1)/(3+2sqrt(2)) find : (i) m^(2) (...

    Text Solution

    |

  9. If x=2sqrt(3)+2sqrt(2) find : (1)/(x)

    Text Solution

    |

  10. If x=2sqrt(3)+2sqrt(2) find : x+(1)/(x)

    Text Solution

    |

  11. If x=2sqrt(3)+2sqrt(2) find : (x+(1)/(x))^(2)

    Text Solution

    |

  12. If x =1-sqrt(2) find the value of (x-(1)/(x))^(3)

    Text Solution

    |

  13. If x = 5-2sqrt(6) find : x^(2)+ (1)/(x^(2))

    Text Solution

    |

  14. Show that : (1)/(3-2sqrt(2))- (1)/(2sqrt(2)-sqrt(7)) + (1)/(sqrt(7)-sq...

    Text Solution

    |

  15. Rationalize the denominator of : (1)/(sqrt(3)-sqrt(2)+1)

    Text Solution

    |

  16. If sqrt(2)= 1.4 and sqrt(3) = 1.7 find the value of each of the corre...

    Text Solution

    |

  17. If sqrt(2)= 1.4 and sqrt(3) = 1.7 find the value of each of the corre...

    Text Solution

    |

  18. If sqrt(2)= 1.4 and sqrt(3) = 1.7 find the value of each of the corre...

    Text Solution

    |

  19. Evalutate : (4-sqrt(5))/(4+sqrt(5))+ (4+sqrt(5))/(4-sqrt(5))

    Text Solution

    |

  20. If (2+sqrt(5))/(2-sqrt(5)) =x and (2-sqrt(5))/(2+sqrt(5)) =y , find th...

    Text Solution

    |