A.5
B.7
C.4
D.2

A.\(\frac{3}{5}\)
B.\(\frac{3}{4}\)
C.\(\frac{5}{4}\)
D.\(\frac{7}{4}\)

A.\( - \frac{9}{2}\)
B.\( - \frac{7}{2}\)
C.\( - \frac{9}{8}\)
D.\( - \frac{5}{2}\)

A.\({A_1}\left( { - 1;\,\,0} \right),\,\,{A_2}\left( {1;\,\,0} \right)\)
B.\({A_1}\left( {0;\,\, - 1} \right),\,\,{A_2}\left( {0;\,\,1} \right)\)
C.\({A_1}\left( {2;\,\,0} \right),\,\,{A_2}\left( { - 2;\,\,0} \right)\)
D.\({A_1}\left( {0;\,\, - 2} \right),\,\,{A_2}\left( {0;\,\,2} \right)\)

A.\(\frac{{\sqrt 5 }}{4}\)
B.\(\frac{{\sqrt 5 }}{5}\)
C.\(\frac{{3\sqrt 5 }}{5}\)
D.\(\frac{{2\sqrt 5 }}{5}\)

A.
B.
C.
D.

A.\(\frac{9}{{16}}\)
B.\(\frac{9}{{13}}\)
C.\(\frac{17}{{16}}\)
D.\(\frac{29}{{16}}\)

A.\(\frac{9}{{16}}\)
B.\(\frac{9}{{13}}\)
C.\(\frac{17}{{16}}\)
D.\(\frac{29}{{16}}\)

A.\(\frac{{25}}{{16}}\)
B.\(\frac{{23}}{{16}}\)
C.\(\frac{{21}}{{16}}\)
D.\(\frac{{25}}{{13}}\)

A.Nếu \({c^2} = {a^2} + {b^2}\) thì \(\left( E \right)\) có các tiêu điểm là \({F_1}\left( {c;\,\,0} \right)\), \({F_2}\left( { - c;\,\,0} \right)\).
B.Nếu \({c^2} = {a^2} + {b^2}\) thì \(\left( E \right)\) có các tiêu điểm là \({F_1}\left( {0;\,\,c} \right)\), \({F_2}\left( {0;\,\, - c} \right)\).
C.Nếu \({c^2} = {a^2} - {b^2}\) thì \(\left( E \right)\) có các tiêu điểm là \({F_1}\left( {c;\,\,0} \right)\), \({F_2}\left( { - c;\,\,0} \right)\).
D.Nếu \({c^2} = {a^2} - {b^2}\) thì \(\left( E \right)\) có các tiêu điểm là \({F_1}\left( {0;\,\,c} \right)\), \({F_2}\left( {0;\,\, - c} \right)\).