Answer:
y = (x² + 1) / (1 – x²)
Explanation:
x = √[(y – 1)/(y + 1)]
We can make y the subject of the expression as shown below:
x = √[(y – 1)/(y + 1)]
Take the square of both side
x² = (y – 1) /(y + 1)
Cross multiply
x²(y + 1) = (y – 1)
Clear bracket
x²y + x² = y – 1
Rearrange
x² + 1 = y – x²y
Factorise
x² + 1 = y(1 – x²)
Divide both side by (1 – x²)
y = (x² + 1) / (1 – x²)