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If a^(2) + (1)/(a^(2))= 47 and a ne 0, f...

If `a^(2) + (1)/(a^(2))= 47 and a ne 0`, find:
`a+ (1)/(a)`

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To solve the problem, we start with the given equation: **Step 1:** Write down the given equation. \[ a^2 + \frac{1}{a^2} = 47 \] **Hint:** Identify the expression you need to manipulate to find \( a + \frac{1}{a} \). --- **Step 2:** Recall the identity for the square of a sum. We know that: \[ \left( a + \frac{1}{a} \right)^2 = a^2 + 2 + \frac{1}{a^2} \] **Hint:** This identity will help us relate \( a^2 + \frac{1}{a^2} \) to \( a + \frac{1}{a} \). --- **Step 3:** Rearrange the identity to express \( a^2 + \frac{1}{a^2} \). From the identity, we can rearrange it to: \[ a^2 + \frac{1}{a^2} = \left( a + \frac{1}{a} \right)^2 - 2 \] **Hint:** This step shows how to express the original equation in terms of the desired quantity. --- **Step 4:** Substitute the value from the original equation into the rearranged identity. Substituting \( 47 \) for \( a^2 + \frac{1}{a^2} \): \[ 47 = \left( a + \frac{1}{a} \right)^2 - 2 \] **Hint:** This substitution will allow you to solve for \( a + \frac{1}{a} \). --- **Step 5:** Solve for \( \left( a + \frac{1}{a} \right)^2 \). Adding \( 2 \) to both sides gives: \[ \left( a + \frac{1}{a} \right)^2 = 47 + 2 \] \[ \left( a + \frac{1}{a} \right)^2 = 49 \] **Hint:** You are now one step away from finding \( a + \frac{1}{a} \). --- **Step 6:** Take the square root of both sides. Taking the square root yields: \[ a + \frac{1}{a} = \pm \sqrt{49} \] \[ a + \frac{1}{a} = \pm 7 \] **Hint:** Remember that the square root can yield both positive and negative values. --- **Final Answer:** Thus, the value of \( a + \frac{1}{a} \) is: \[ a + \frac{1}{a} = 7 \text{ or } -7 \] ---
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ICSE-EXPANSIONS-Exercise 4(B)
  1. Find the cube of: 2a + (1)/(2a) (a ne 0)

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  2. Find the cube of: 3a - (1)/(a) (a ne 0)

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  3. If a^(2) + (1)/(a^(2))= 47 and a ne 0, find: a+ (1)/(a)

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  4. If a^(2) + (1)/(a^(2))= 47 and a ne 0, find: a^(3) + (1)/(a^(3))

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  5. If a^(2) + (1)/(a^(2)) = 18 and a ne 0, find: a- (1)/(a)

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  6. If a^(2) + (1)/(a^(2)) = 18 and a ne 0, find: a^(3)- (1)/(a^(3))

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  7. If a + (1)/(a)= p and a ne 0, then show that: a^(3) + (1)/(a^(3))= p (...

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  8. If a + 2b= 5, then show that: a^(3) + 8b^(3) + 30ab = 125

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  9. If (a + (1)/(a))^(2) = 3 and a ne 0, then show that: a^(3) + (1)/(a^(3...

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  10. If a + 2b + c= 0, then show that: a^(3) + 8b^(3) + c^(3)= 6abc

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  11. Use property to evaluate: 13^(3) + (-8)^(3) + (-5)^(3)

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  12. Use property to evaluate: 7^(3) + 3^(3) + (-10)^(3)

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  13. Use property to evaluate: 9^(3) -5^(3) - 4^(3)

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  14. Use property to evaluate: 38^(3) + (-26)^(3) + (-12)^(3)

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  15. If a ne 0 and a - (1)/(a)= 3, find : a^(2) + (1)/(a^(2))

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  16. If a ne 0 and a - (1)/(a)= 3, find : a^(3)- (1)/(a^(3))

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  17. If a ne 0 and a - (1)/(a)= 4, find a^(2) + (1)/(a^(2))

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  18. If a ne 0 and a - (1)/(a)= 4, find a^(4) + (1)/(a^(4))

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  19. If a ne 0 and a - (1)/(a)= 4, find a^(3)- (1)/(a^(3))

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  20. If x ne 0 and x + (1)/(x) = 2, then show that: x^(2)+ (1)/(x^(2))= x^(...

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