y=【根号(x²-9)-根号(9-x²)+1】/(x-3),求-5x-6y的平方根
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![y=【根号(x²-9)-根号(9-x²)+1】/(x-3),求-5x-6y的平方根](/uploads/image/z/179312-32-2.jpg?t=y%3D%E3%80%90%E6%A0%B9%E5%8F%B7%EF%BC%88x%26%23178%3B-9%EF%BC%89-%E6%A0%B9%E5%8F%B7%EF%BC%889-x%26%23178%3B%EF%BC%89%2B1%E3%80%91%2F%EF%BC%88x-3%EF%BC%89%2C%E6%B1%82-5x-6y%E7%9A%84%E5%B9%B3%E6%96%B9%E6%A0%B9)
y=【根号(x²-9)-根号(9-x²)+1】/(x-3),求-5x-6y的平方根
y=【根号(x²-9)-根号(9-x²)+1】/(x-3),求-5x-6y的平方根
y=【根号(x²-9)-根号(9-x²)+1】/(x-3),求-5x-6y的平方根
要保证y有意义,需要:x^2-9≧0、9-x^2≧0,∴x^2=9.
要保证y有意义,还需要x≠3,∴由x^2=9,得:x=-3.
∴y=1/(-3-3)=-1/6.
∴-5x-6y=-5×(-3)-6×(-1/6)=15+1=16.
∴(-5x-6y)的平方根是:-4、4.