Question

Find the value of x² + 1/x²where (i)x+1/x=3. (ii) x-1/x=11​

Answer 1

Step-by-step explanation:

(1) x+1/x=3.

• squaring both sides
• (x+1/x)²=(3)²
• x² + 1/x² + 1 = 9
• x² + 1/x² =9-1
• x² + 1/x²=8

(2) x-1/x=11

squaring both sides

(x-1/x)²=(11)²

x² + 1/x² - 1 = 121

x² + 1/x² =121+1

x² + 1/x²=122