已知x=-5,y=1\5,n为自然数,则x的2n+1次方·y的2n+2次方
问题描述：
已知x=-5,y=1\5,n为自然数,则x的2n+1次方·y的2n+2次方
答
x^(2n+1)*y^(2n+2)
=x^(2n+1)*y^(2n+1)*y
=(xy)^(2n+1)*y
=(-5*(1/5))^(2n+1)*(1/5)
=(-1)^(2n+1)*(1/5)
=-1/5
答
x=-5,y=1\5
则xy=-1
x的2n+1次方·y的2n+2次方
=x的2n+1次方·y的2n+1次方·y
=(xy)的2n+1次方·y
=(-1)的2n+1次方·y
2n+1是奇数
=-y
=1\5