If p+1/p= 9, find the value of p³+1/p³
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Answered by
1
the answer is (9)cube or 729
AverageNazi:
nah
the answer is 702
Answered by
1
p+1/p=9
Squaring on both sides we get,
p²+1/p²+2p×1/p=81
p²+1/p²+2=81
p²+1/p²=79
Now let p³+1/p³ be x
p³+1/p³=x
(p+1/p)(p²-p(1/p)+1/p²)=x
9(79-1)=x
9(78)=x
x=702
Hence p³+1/p³=702
Squaring on both sides we get,
p²+1/p²+2p×1/p=81
p²+1/p²+2=81
p²+1/p²=79
Now let p³+1/p³ be x
p³+1/p³=x
(p+1/p)(p²-p(1/p)+1/p²)=x
9(79-1)=x
9(78)=x
x=702
Hence p³+1/p³=702
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