Question

Pls help 2 Question

Answer 1

Answer:

1.320  ,

2.322

Step-by-step explanation:

1. Given that,

a+1/a=18

now,

(a- 1/a)² =( a+1/a)² - 4a. 1/a         [(a- b)² =( a+b)² - 4a. b  ]

           =18² - 4 . 1                      [as, a . 1/a =1 ]    

            =324 - 4

            =320

2.Given that,

a - 1/a=4

now,

a⁴+(1/a)⁴

=(a²)² + (1/a²)²                             [a⁴=(a²)² & (1/a)⁴=(1/a²)²]  

=(a²+1/a²) ²- 2 a². (1/a²)                [a²+b²=(a+b)²-2ab]

=[(a - 1/a)² +2.a. 1/a]² - 2               [a²+b²=(a-b)²+2ab]

=[4²+2]² -2

=[16+2]²-2

=18²-2

=324-2

=322