解答
展开 (21−23i)16
解答
−21+23i
求解步骤
(21−23i)16
使用二项式定理: (a+b)n=i=0∑n(in)a(n−i)bia=21,b=−23i
=i=0∑16(i16)(21)(16−i)(−23i)i
展开求和
=0!(16−0)!16!(21)16(−23i)0+1!(16−1)!16!(21)15(−23i)1+2!(16−2)!16!(21)14(−23i)2+3!(16−3)!16!(21)13(−23i)3+4!(16−4)!16!(21)12(−23i)4+5!(16−5)!16!(21)11(−23i)5+6!(16−6)!16!(21)10(−23i)6+7!(16−7)!16!(21)9(−23i)7+8!(16−8)!16!(21)8(−23i)8+9!(16−9)!16!(21)7(−23i)9+10!(16−10)!16!(21)6(−23i)10+11!(16−11)!16!(21)5(−23i)11+12!(16−12)!16!(21)4(−23i)12+13!(16−13)!16!(21)3(−23i)13+14!(16−14)!16!(21)2(−23i)14+15!(16−15)!16!(21)1(−23i)15+16!(16−16)!16!(21)0(−23i)16
化简 0!(16−0)!16!(21)16(−23i)0:655361
化简 1!(16−1)!16!(21)15(−23i)1:−40963i
化简 2!(16−2)!16!(21)14(−23i)2:819245i2
化简 3!(16−3)!16!(21)13(−23i)3:−40961053i3
化简 4!(16−4)!16!(21)12(−23i)4:163844095i4
化简 5!(16−5)!16!(21)11(−23i)5:−409624573i5
化简 6!(16−6)!16!(21)10(−23i)6:819227027i6
化简 7!(16−7)!16!(21)9(−23i)7:−4096193053i7
化简 8!(16−8)!16!(21)8(−23i)8:32768521235i8
化简 9!(16−9)!16!(21)7(−23i)9:−4096579153i9
化简 10!(16−10)!16!(21)6(−23i)10:8192243243i10
化简 11!(16−11)!16!(21)5(−23i)11:−4096663393i11
化简 12!(16−12)!16!(21)4(−23i)12:16384331695i12
化简 13!(16−13)!16!(21)3(−23i)13:−4096255153i13
化简 14!(16−14)!16!(21)2(−23i)14:819232805i14
化简 15!(16−15)!16!(21)1(−23i)15:−409621873i15
化简 16!(16−16)!16!(21)0(−23i)16:655366561i16
=655361−40963i+819245i2−40961053i3+163844095i4−409624573i5+819227027i6−4096193053i7+32768521235i8−4096579153i9+8192243243i10−4096663393i11+16384331695i12−4096255153i13+819232805i14−409621873i15+655366561i16
化简 655361−40963i+819245i2−40961053i3+163844095i4−409624573i5+819227027i6−4096193053i7+32768521235i8−4096579153i9+8192243243i10−4096663393i11+16384331695i12−4096255153i13+819232805i14−409621873i15+655366561i16:−21+23i
=−21+23i