If a^1/3-b^1/3=2 and ab=1, then write the value of a^3-b^3
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Solution
Given That :-
- a ^(1/3) - b^(1/3) = 2 ------(1)
- ab = 1 -----------------------(2)
Find :-
- Value of a³ - b³
Explanation
First take Cube of equ(1)
➥ a ^(3 × 1/3) - b^(3× 1/3) = 2³
➥ a - b = 8 ---------(3)
Again, take square of equ(3)
➥ (a - b)² = 8²
➥ (a² + b² - 2ab) = 64
➥ a² + b² = 64 + 2ab
keep Value by equ(2)
➥ a² + b² = 64 - 2 × 1
➥ a² + b² = 64 - 2
➥ a² + b² = 62 --------------(4)
Now, Using
★ ( a³ - b³ ) = (a-b)(a²+b²+ab)
keep All above values by equ(2) , (3) & (4)
➥ (a³ - b³ ) = (8)(62+1)
➥ (a³ - b³ ) = 8 × 63
➥ (a³ - b³ ) = 504
Hence
- Value of (a³ - b³ ) be 504
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Answer:
504 is answer of question
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