Posted by
**zinnia** on
.

Find equations for the asymptotes of the hyperbola x2/9 - y2/81 = 1

Rewrite the equation as

(x/3)^2 - (y/9)^2 = 1

When both x and y are very large in absolute value, the "1" on the right is negligible in comparison, so y/9 approaches +/- x/3

The asymptotes are therefore

y = 3x and y = -3x.