can you solve this problem
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it is a alegabric equation
chiragpc:
algebraic and trigonometry
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Answer:
a - 1/a = ±4
a³ - 1/a³ = ±76
Step-by-step explanation:
Write k = a - 1/a.
Then k² = a² - 2(a)(1/a) + 1/a² = a² + 1/a² - 2 = 18 - 2 = 16.
So k = 4 or k = -4.
Cubing k, we have
k³ = ( a - 1/a )³
= a³ - 3 a² (1/a) + 3 a (1/a)² - 1/a³
= a³ - 3a + 3/a - 1/a³
= a³ - 1/a³ - 3 ( a - 1/a )
= a³ - 1/a³ - 3 k
Hence
a³ - 1/a³ = k³ + 3k = ± ( 64 + 12 ) = ±76.
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