1.

The sum of two numbers is 6 times their geometric means, show that the numbers are in the ratio (3 + 2√2 ) : (3 – 2√2).

Answer»

Let the two numbers be a and b. 

GM = √ab 

According to the given condition, 

a + b = 6√ab …(1) 

(a + b)2 = 36ab 

Also, 

(a – b)2 = (a + b)2 – 4ab 

= 36ab – 4ab 

= 32ab 

⇒ a – b = √32ab 

= 4√2ab …..(2) 

Adding (1) and (2), we obtain 

2a = (6 + 4√2)√ab 

a = (3 + 2√2)√ab 

substituting the value of a in (1), we obtain, 

b =(3 – 2√2)√ab

\(\therefore\) \(\cfrac{3 + 2\sqrt{2}}{3-2\sqrt{2}}\)

Thus, the required ratio is (3+2√2) : 3–2√2.



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