PLEASE HELP WILL MARK BRAINLIEST
Which is the equation of a hyperbola with directrices at x = ±2 and foci at (4, 0) and (−4, 0)?

x squared over 8 minus y squared over 8 equals 1
x squared over 8 minus y squared over 16 equals 1
y squared over 8 minus x squared over 8 equals 1
y squared over 16 minus x squared over 8 equals 1

Respuesta :

The equation of the hyperbola is:

[tex]\frac{x^2}{8} - \frac{y^2}{8} = 1[/tex]

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  • Directrices at [tex]x = \pm 2[/tex]
  • Foci at [tex]x = \pm 4[/tex]

They are both in the x-axis, and the center is (0,0), which means that the equation is:

[tex]\frac{x^2}{a^2} - \frac{y^2}{b^2} = 1[/tex]

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Directrices at [tex]x = \pm 2[/tex] means that:

[tex]\frac{a^2}{c} = 2[/tex]

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Foci at [tex]x = \pm 4[/tex] means that:

[tex]c^2 = 4^2 = 16 \rightarrow c = 4[/tex]

Thus:

[tex]a^2 = 2c = 2(4) = 8[/tex]

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For b, we have that:

[tex]a^2 + b^2 = c^2[/tex]

[tex]8 + b^2 = 16[/tex]

[tex]b^2 = 8[/tex]

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Thus, since a and b have been found, the equation of the hyperbola is:

[tex]\frac{x^2}{8} - \frac{y^2}{8} = 1[/tex]

A similar problem is given at https://brainly.com/question/20409089