Question

Find y sq+1/y sq and y^4+1/y^4 if y-1/y =9​

Answer 1

Step-by-step explanation:

Here

${y}^{2} + \frac{1}{ {y}^{2} } = {(y - \frac{1}{y} ) }^{2} + 2 \\ = {(9)}^{2} + 2 \\ = 81 + 2 \\ = 83$

${y}^{4} + \frac{1}{ {y}^{4} } = {( {y}^{2} - \frac{1}{ {y}^{2} } ) }^{2} + 2 \\ = {(83)}^{2} + 2 \\ = 6889 + 2 \\ = 6892$