Question

If x-1 = -2, find x^2+1/x^2.

Answer 1

ANSWER:

(x² + 1) / x² = 1

GIVEN:

x - 1 = -2

x = -1

TO FIND:

(x² + 1) / x²

EXPLANATION:

SUBSTITUTE x = -1 IN (x² + 1) / x²

(x² + 1) / x² = ((- 1)² + 1) / (-1)²

(x² + 1) / x² = (1 + 1 ) / 1

(x² + 1) / x² = 2/1

(x² + 1) / x² = 1

EXTRA INFORMATION:

USEFUL FORMULAE:

• A² + B² = (A + B)² - 2AB

• A² - B² = (A + B)(A-B)

• (A + B)² = A² + B² + 2AB

• (A - B)² = A² + B² - 2AB

• (A + 1/A)² = A² + 1/A² + 2

• (A - 1/A)² = A² + 1/A² - 2