What are the directrices of the ellipse given by the equation

Question

 x^2/36+y^2/100=1

Answer 1

The given ellipse eqution is x^2/36+y^2/100 = 1

The general formula of  ellipse is x^2/a^2+y^2/b^2 = 1

Where a^2 = 100 and b^2 = 36

c^2 = a^2 - b^2

c^2 = 100 -36

c^2 = 64

Take square root each side

Therefore c = 8

The directrices of the ellipse formula is x = ± a^2/c

 x = ± 100/8

x = ± 12.5

The solution is x = ± 12.5.