Question

if the mean of y and 1/y is z, then mean of y² and 1/y² is ?

a. z² - 2
b. z² + 2
c. 2z² - 1
d. 4z²- 2 ​

Answer 1

Answer:

Z²-2

Step-by-step explanation:

1. y + 1/y = z

2. ( y + 1/y )² = ( z)²

3. y² + 1/y² + 2 × y × 1/y = z²

4. y² + 1 / y² = z² - 2

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Answer 2

Answer:

Step-by-step explanation: Y+1/Y= Z

(Y+1/Y)² = (Z)²

FORMULA = (A+B)²= A²+B²+2AB

Y²+1/Y²+2*Y*1/Y = Z²

Y²+1/Y²+2 =Z²

Y²+1/Y²=Z²-2

FINAL ANSWER = Z²-2