k方和公式是什么?a^k-b^k=(a-b)(a^(k-1)+a^(k-2)b+...+b^(k-1))那么a^k+b^k=...1+x+x^2+...+x^(n-1)=(1-x^n)/(1-x)令x=-b/a即当n为偶数时1+(-b/a)+...+(-b/a)^(n-1)=(a^n-b^n)/(a^(n-1)(a+b))当n为奇数时,1+(-b/a)+...+(-b/a)^(n-1)=(a^n+b^n)
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/27 20:18:19
![k方和公式是什么?a^k-b^k=(a-b)(a^(k-1)+a^(k-2)b+...+b^(k-1))那么a^k+b^k=...1+x+x^2+...+x^(n-1)=(1-x^n)/(1-x)令x=-b/a即当n为偶数时1+(-b/a)+...+(-b/a)^(n-1)=(a^n-b^n)/(a^(n-1)(a+b))当n为奇数时,1+(-b/a)+...+(-b/a)^(n-1)=(a^n+b^n)](/uploads/image/z/4914463-31-3.jpg?t=k%E6%96%B9%E5%92%8C%E5%85%AC%E5%BC%8F%E6%98%AF%E4%BB%80%E4%B9%88%3Fa%5Ek-b%5Ek%3D%28a-b%29%28a%5E%28k-1%29%2Ba%5E%28k-2%29b%2B...%2Bb%5E%28k-1%29%29%E9%82%A3%E4%B9%88a%5Ek%2Bb%5Ek%3D...1%2Bx%2Bx%5E2%2B...%2Bx%5E%28n-1%29%3D%281-x%5En%29%2F%281-x%29%E4%BB%A4x%3D-b%2Fa%E5%8D%B3%E5%BD%93n%E4%B8%BA%E5%81%B6%E6%95%B0%E6%97%B61%2B%28-b%2Fa%29%2B...%2B%28-b%2Fa%29%5E%28n-1%29%3D%28a%5En-b%5En%29%2F%28a%5E%28n-1%29%EF%BC%88a%2Bb%29%29%E5%BD%93n%E4%B8%BA%E5%A5%87%E6%95%B0%E6%97%B6%EF%BC%8C1%2B%28-b%2Fa%29%2B...%2B%28-b%2Fa%29%5E%28n-1%29%3D%28a%5En%2Bb%5En%29)
k方和公式是什么?a^k-b^k=(a-b)(a^(k-1)+a^(k-2)b+...+b^(k-1))那么a^k+b^k=...1+x+x^2+...+x^(n-1)=(1-x^n)/(1-x)令x=-b/a即当n为偶数时1+(-b/a)+...+(-b/a)^(n-1)=(a^n-b^n)/(a^(n-1)(a+b))当n为奇数时,1+(-b/a)+...+(-b/a)^(n-1)=(a^n+b^n)
k方和公式是什么?
a^k-b^k=(a-b)(a^(k-1)+a^(k-2)b+...+b^(k-1))
那么a^k+b^k=...
1+x+x^2+...+x^(n-1)=(1-x^n)/(1-x)
令x=-b/a
即当n为偶数时
1+(-b/a)+...+(-b/a)^(n-1)=(a^n-b^n)/(a^(n-1)(a+b))
当n为奇数时,
1+(-b/a)+...+(-b/a)^(n-1)=(a^n+b^n)/(a^(n-1)(a+b))
所以a^n+b^n=(1+(-b/a)+...+(-b/a)^(n-1))(a^(n-1)(a+b))=(a+b)(a^(n-1)-a^(n-2)b+...+b^(n-1))
看你们回答得都不怎么样,我去问老师了
到最后一天看到哪个顺眼的就给你最佳好了
k方和公式是什么?a^k-b^k=(a-b)(a^(k-1)+a^(k-2)b+...+b^(k-1))那么a^k+b^k=...1+x+x^2+...+x^(n-1)=(1-x^n)/(1-x)令x=-b/a即当n为偶数时1+(-b/a)+...+(-b/a)^(n-1)=(a^n-b^n)/(a^(n-1)(a+b))当n为奇数时,1+(-b/a)+...+(-b/a)^(n-1)=(a^n+b^n)
用平方差的公式 可以推出来
将两个式子对应相乘 再用右边的答案除以1式的左边
将两个式子对应相乘 再用右边的答案除以1式的左边