Question 1170472
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Foci at (-4,0) and (4,0) means the equation is of the general form<br>
{{{x^2/a^2-y^2/b^2 = 1}}}<br>
a is the distance from the center to each end of the transverse axis (i.e., to each vertex); b is the distance from the center to each end of the conjugate axis (i.e. to each co-vertex).  a and b are related by<br>
{{{c^2 = a^2+b^2}}}<br>
where c is the distance from the center to each focus.<br>
The eccentricity is c/a.<br>
The given information is c=4 and eccentricity = 5/4.<br>
(1) Use c and the eccentricity to find a.<br>
(2) Use {{{c^2 = a^2+b^2}}} to find b.<br>
(3) Plug the a^2 and b^2 values into the general form of the equation.<br>