a+1/a=4 求(1)axa+1/axa (2) axaxaxa+1/axaxaxa (3)axaxa+1/axaxa

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a+1/a=4 求(1)axa+1/axa (2) axaxaxa+1/axaxaxa (3)axaxa+1/axaxa

a+1/a=4 求(1)axa+1/axa (2) axaxaxa+1/axaxaxa (3)axaxa+1/axaxa
a+1/a=4 求(1)axa+1/axa (2) axaxaxa+1/axaxaxa (3)axaxa+1/axaxa

a+1/a=4 求(1)axa+1/axa (2) axaxaxa+1/axaxaxa (3)axaxa+1/axaxa
a+1/a=4
两边平方
a²+2+1/a²=16
a²+1/a²=14
两边平方
a⁴+2+1/a⁴=196
所以a⁴+1/⁴=194
a³+1/a³
=(a+1/a)(a²-a*1/a+1/a²)
=4*(14-1)
=52