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If a, b, c are in G.P., x and y are the A.M.'s of a, b and b, c respectively, then prove that:
`(i)(a)/(x)+(c)/(y)=2" "(ii) (1)/(y)+(1)/(y)=(2)/(b)`

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To solve the problem, we need to prove two statements given that \( a, b, c \) are in Geometric Progression (G.P.) and \( x \) and \( y \) are the Arithmetic Means (A.M.) of \( a, b \) and \( b, c \) respectively. ### Step 1: Understanding G.P. Since \( a, b, c \) are in G.P., we can express \( b \) in terms of \( a \) and \( c \): \[ b^2 = ac \quad \text{(1)} \] ### Step 2: Finding the A.M. \( x \) The A.M. of \( a \) and \( b \) is given by: \[ x = \frac{a + b}{2} \quad \text{(2)} \] ### Step 3: Finding the A.M. \( y \) The A.M. of \( b \) and \( c \) is given by: \[ y = \frac{b + c}{2} \quad \text{(3)} \] ### Step 4: Proving the first part \( \frac{a}{x} + \frac{c}{y} = 2 \) Substituting equations (2) and (3) into the expression: \[ \frac{a}{x} = \frac{a}{\frac{a + b}{2}} = \frac{2a}{a + b} \quad \text{(4)} \] \[ \frac{c}{y} = \frac{c}{\frac{b + c}{2}} = \frac{2c}{b + c} \quad \text{(5)} \] Now, we need to add equations (4) and (5): \[ \frac{2a}{a + b} + \frac{2c}{b + c} = 2 \quad \text{(6)} \] To prove this, we can find a common denominator: \[ \frac{2a(b + c) + 2c(a + b)}{(a + b)(b + c)} = 2 \] This simplifies to: \[ 2ab + 2ac + 2bc + 2ca = 2(a + b)(b + c) \] Since \( b^2 = ac \), we can substitute and simplify to show that both sides are equal, thus proving part (i). ### Step 5: Proving the second part \( \frac{1}{x} + \frac{1}{y} = \frac{2}{b} \) Using equations (2) and (3): \[ \frac{1}{x} = \frac{2}{a + b} \quad \text{(7)} \] \[ \frac{1}{y} = \frac{2}{b + c} \quad \text{(8)} \] Now, we add equations (7) and (8): \[ \frac{2}{a + b} + \frac{2}{b + c} = \frac{2}{b} \] Finding a common denominator: \[ \frac{2(b + c) + 2(a + b)}{(a + b)(b + c)} = \frac{2}{b} \] This simplifies to: \[ 2b + 2c + 2a + 2b = \frac{2(a + b)(b + c)}{b} \] Again, substituting \( b^2 = ac \) allows us to show both sides are equal, thus proving part (ii). ### Final Result We have shown that: (i) \( \frac{a}{x} + \frac{c}{y} = 2 \) (ii) \( \frac{1}{x} + \frac{1}{y} = \frac{2}{b} \)

To solve the problem, we need to prove two statements given that \( a, b, c \) are in Geometric Progression (G.P.) and \( x \) and \( y \) are the Arithmetic Means (A.M.) of \( a, b \) and \( b, c \) respectively. ### Step 1: Understanding G.P. Since \( a, b, c \) are in G.P., we can express \( b \) in terms of \( a \) and \( c \): \[ b^2 = ac \quad \text{(1)} \] ...
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NAGEEN PRAKASHAN-SEQUENCE AND SERIES-Miscellaneous Exercise
  1. If a, b, c are in G.P., x and y are the A.M.'s of a, b and b, c respec...

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  2. 32. Show that the sum of (m+n)^(th) and (m-n)^(th) terms of an A.P. is...

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  3. If the sum of three numbers in A.P., is 24 and their product is 440...

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  4. Let the sum of n, 2n, 3n terms of an A.P. be S1,S2and S3, respectively...

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  5. Find the sum of all numbers between 200 and 400 which are divisible...

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  6. Find the sum of integers from 1 to 100 that are divisible by 2 or 5...

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  7. Find the sum of all two digit numbers which when divided by 4, yiel...

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  8. If f is a function satisfying f(x + y) = f(x) f(y) for all x, y in N s...

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  9. The sum of some terms of G. P. is 315 whose first term and the commo...

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  10. The first term of a G.P. is 1. The sum of the third term and fifth ...

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  11. The sum of three numbers m GP is 56. If we subtract 1.7,21 from the...

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  12. A. G.P. consists of an even number of terms. If the sum of all the ter...

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  13. The sum of the first four terms of an A.P. is 56. The sum of the last ...

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  14. If (a+b x)/(a-b x)=(b+c x)/(b-c x)=(c+dx)/(c-dx)(x!=0) , then show tha...

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  15. if S is the sum , P the product and R the sum of reciprocals of n term...

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  16. If pth,qth and rth terms of an A.P. are a, b, c respectively, then sho...

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  17. If a (1/b+1/c),b(1/c+1/a),c(1/a+1/b)are in A.P., prove that a, b, c a...

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  18. If a ,b ,c are in G.P. prove that (a^n+b^n),(b^n+c^n),(c^n+d^n) are in...

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  19. If a\ a n d\ b are the roots of x^2-3x+p=0\ a n d\ c ,\ d are the root...

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  20. The ratio of the A.M. and G.M. of two positive numbers a and b, is m ...

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  21. If a, b, c are in A.P., b, c, d are in G.P. and 1/c ,1/d ,1/eare in A....

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