Question

If a^2 + 1/a^2 = 18 a not equal to 0 , find (1) a - 1/a (2) a^3 - 1/a^3​

Answer 1

$\huge{\mathcal{\underline{\red{AnSWer}}}}$

$a {}^{2} + \frac{1}{a {}^{2} } = 18$

we know that

$(a - \frac{1}{a {}^{} } ) {}^{2} = a {}^{2} - 2 a \times \frac{1}{a} + (\frac{1}{a {}^{} } ) {}^{2}$

$→(a - \frac{1}{a {}^{} } ) {}^{2} = 18 - 2$

$→(a - \frac{1}{a {}^{} } ) {}^{2} = 16$

$→(a - \frac{1}{a {}^{} } ) {}^{} = ± \sqrt{16}$

$\pink{\boxed{\sf (a - \frac{1}{a {}^{} } ) {}^{} = ± {4} }}$

Answer 2

Answer:

please see the attachment