已知数列-1,a1,a2,-4成等差数列,-1,b1,b2,b3,-4成等比数列,则(a2-a1)/b2的值为?
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![已知数列-1,a1,a2,-4成等差数列,-1,b1,b2,b3,-4成等比数列,则(a2-a1)/b2的值为?](/uploads/image/z/5181561-9-1.jpg?t=%E5%B7%B2%E7%9F%A5%E6%95%B0%E5%88%97-1%2Ca1%2Ca2%2C-4%E6%88%90%E7%AD%89%E5%B7%AE%E6%95%B0%E5%88%97%2C-1%2Cb1%2Cb2%2Cb3%2C-4%E6%88%90%E7%AD%89%E6%AF%94%E6%95%B0%E5%88%97%2C%E5%88%99%EF%BC%88a2-a1%29%2Fb2%E7%9A%84%E5%80%BC%E4%B8%BA%3F)
已知数列-1,a1,a2,-4成等差数列,-1,b1,b2,b3,-4成等比数列,则(a2-a1)/b2的值为?
已知数列-1,a1,a2,-4成等差数列,-1,b1,b2,b3,-4成等比数列,则(a2-a1)/b2的值为?
已知数列-1,a1,a2,-4成等差数列,-1,b1,b2,b3,-4成等比数列,则(a2-a1)/b2的值为?
-1,a1,a2,-4成等差数列,公差d
-4=-1+3d,d=-1,∴a2-a1=d=-1
-1,b1,b2,b3,-4成等比数列
-4=-1*q^4,q^4=4,q^2=2
b2=-1*q^2=-2
∴(a2-a1)/b2=-1/-2=1/2