椭圆x²/4+y²/a²=1与双曲线x²/a-y²/2=1焦点相同,则a=
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![椭圆x²/4+y²/a²=1与双曲线x²/a-y²/2=1焦点相同,则a=](/uploads/image/z/1022960-56-0.jpg?t=%E6%A4%AD%E5%9C%86x%26%23178%3B%2F4%2By%26%23178%3B%2Fa%26%23178%3B%3D1%E4%B8%8E%E5%8F%8C%E6%9B%B2%E7%BA%BFx%26%23178%3B%2Fa-y%26%23178%3B%2F2%3D1%E7%84%A6%E7%82%B9%E7%9B%B8%E5%90%8C%2C%E5%88%99a%3D)
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椭圆x²/4+y²/a²=1与双曲线x²/a-y²/2=1焦点相同,则a=
椭圆x²/4+y²/a²=1与双曲线x²/a-y²/2=1焦点相同,则a=
椭圆x²/4+y²/a²=1与双曲线x²/a-y²/2=1焦点相同,则a=
双曲线x²/a-y²/2=1的焦点在x轴
为c²=a+2
所以椭圆x²/4+y²/a²=1的焦点也在x轴
c²=4-a²
所以4-a²=a+2
解之得 a=-2或1
由双曲线x²/a-y²/2=1
可知a>0(因为-y²/2中有负号)
所以a=1