Question

X-1/x= root 21the value of x squared+1/x squared into x+1/x is

Answer 1

Answer:

x - 1/x = √21

squaring both the sides

(x - 1/x)² = √21²

x² + (1/x)² - 2 × x × 1/x = 21

x² + 1/x² - 2 = 21

x² + 1/x² = 21+2

x² + 1/x² = 23