怎样证明(2k+1)^2+1/3*k*(4k^2-1)=1/3(k+1)[4(k+1)^2-1]

问题描述:

怎样证明(2k+1)^2+1/3*k*(4k^2-1)=1/3(k+1)[4(k+1)^2-1]

左边=(2k+1)^2+1/3*k*(4k^2-1)=(2k+1)^2+1/3*k(2k+1)(2k-1)=(2k+1)(5/3k+1+2/3k^)=1/3(2k+1)(2k^+5k+3)=1/3(2k+1)(k+1)(2k+3)右边=1/3(k+1)(4k^+8k+3)=1/3(k+1)(2k+1)(2k+3)左边=...