Geo5.3.10

From Example Problems
Jump to: navigation, search

Write down the equations of the directrices of the hyperbola {\frac  {x^{2}}{144}}-{\frac  {y^{2}}{36}}=1\,

From the given equation a^{2}=144,a=12,b^{2}=36,b=6\,

b^{2}=a^{2}(e^{2}-1),36=144(e^{2}-1),e^{2}={\frac  {180}{144}}={\frac  {5}{4}},e={\frac  {{\sqrt  {5}}}{2}}\,

Equations of directrices arex=\pm {\frac  {a}{e}},x=\pm {\frac  {24}{{\sqrt  {5}}}}\,

{\sqrt  {5}}x-24=0,{\sqrt  {5}}x+24=0\,

Main Page:Geometry:Hyperbola