Question

if a= 1-√2 find the value of ( a- 1/ a ) ²​

Answer 1

Answer:

4(3-2√2)

Step-by-step explanation:

(a-1/a)²=a²+1/a²-2a*1/a

=a²+1/a²-2

=a4+1-2a² (1)

now

a²=(1-√2)²=1+2-2√2=3-2√2

a4=a²)²=(3-2√2)²=9+8-2*3*2√2=17-12√2

put it in (1)

17-12√2+1-2(3-2√2)

17-12√2+1-6+4√2

18-6-12√2+4√2

12-8√2

4(3-2√2)

I think it is helpful for you