Question

Question 5
a) If a -1/a =4, find the value of a² + 1/a2​

Answer 1

Answer:

$a - \frac{1}{a} = 4 \\ \\ squaring \: both \: side \\ \\ {(a - \frac{1}{a} )}^{2} = {(4)}^{2} \\ \\ {a}^{2} + \frac{1}{ {a}^{2} } - 2 \times a \times \frac{1}{a} = 16 \\ \\ {a}^{2} + \frac{1}{ {a}^{2} } - 2 = 16 \\ \\{ \pink{ {a}^{2} + \frac{1}{ {a}^{2} } = 18}}$