y=x^3-3x^2+3x+1反函数帮忙算一下y=x^3-3x^2+3x+1的反函数

y=x^3-3x^2+3x+1反函数帮忙算一下y=x^3-3x^2+3x+1的反函数
y=x^3-3x^2+3x+1反函数
帮忙算一下y=x^3-3x^2+3x+1的反函数

y=x^3-3x^2+3x+1反函数帮忙算一下y=x^3-3x^2+3x+1的反函数
y-2=x³-3x²+3x-1=(x-1)³
x-1=(y-2)^(1/3)
所以反函数y=(x-2)^(1/3)+1

S9 = 18
(a1 + a9)*9 /2 = 18
a1 + a9 = 4
a1 + a1 + (9-1)*d = 4
a1 + 4d = 2
a1 = 2-4d
a(n-4)=30
a1 + (n-4-1)*d = 30
a1 + (n-5)d = 30
2-4d + (n-5)d = 30
(n - 9)d ...

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S9 = 18
(a1 + a9)*9 /2 = 18
a1 + a9 = 4
a1 + a1 + (9-1)*d = 4
a1 + 4d = 2
a1 = 2-4d
a(n-4)=30
a1 + (n-4-1)*d = 30
a1 + (n-5)d = 30
2-4d + (n-5)d = 30
(n - 9)d = 28
Sn = 256
(a1 + an)*n/2 = 256
[a1 + a1 + (n-1)d]*n = 512
[2a1 + (n-1)d]*n = 512
[4 - 8d + (n-1)d]*n = 512
[4 + (n-9)d]*n = 512
[4 + 28]*n = 512
32 n = 512

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