Solution
Step 1: Find the foci of the given ellipse
The equation of the ellipse is:
Comparing with a2x2+b2y2=1:
a2=25⟹a=5
b2=9⟹b=3
The eccentricity ee of the ellipse is:
ee=1−a2b2=1−259=2516=54
The foci of the ellipse are (±aee,0):
Step 2: Use the hyperbola's properties
The foci of the hyperbola are the same as the ellipse, so for the hyperbola:
Given that the eccentricity of the hyperbola eh=2:
Step 3: Find B2 for the hyperbola
For a hyperbola, the relation between A, B, and e is:
Substituting the values:
Step 4: Write the equation of the hyperbola
The standard equation of the hyperbola is:
Substituting A2=4 and B2=12:
Conclusion
The equation of the hyperbola is 4x2−12y2=1.
The correct option is (a).