Question

for this guys this is what im asking for

Answer 1

Answer:

Sorry, I have the answers to no. 7 and 9 only.

Step-by-step explanation:

7. If x = root 2 + 1

To find : (x-1/x)2

= x2 + 1/x2 - 2

= (root 2 + 1)2 + 1/(root 2 + 1) - 2

= {(root 2) 2+ (1)2 + 2.(root2 * 1)} + {(1/root 2)2 + (1)2 + 2 (1/root 2 * 1)

= { 2 + 1 + 2 root 2 } +{ 1/2 + 1 + 2/root 2} - 2

= (3 + 2 root 2) + ( 3/ 2 + 2/ root 2) - 2

= (6 + 4 root 2 + 3 + 2 root 2 - 4)/2

= (5 + 6 root 2)/2

9. Given, a = root 3 + root 2/ root 3 - root 2

b = root 3 - root 2 / root 3 + root 2

thus, a+b = ( root 3 + root 2/ root 3 - root 2 ) + (root 3 - root 2 / root 3 + root 2)

= ( root 3 + root 2)2 + ( root 3 - root 2)2 /( root 3 - root 2)* ( root 3 - root 2)

= {3 + 2 + 2(root 3 * root 2) + 3 + 2 - 2 ( root 3* root 2)} /( root 3) 2-(root 2)2

= ( 3+ 2 + 3 + 2)/ 3 - 2

= 10 / 1

= 10

thus, ( a+ b) ^ 2 = ( 10) ^ 2 = 100

Ans: (a + b)^ 2 = 100