if X + 1 divided by x is equal to 3 find X square + 1 / x square and x cube + 1 / x cube
Answers
Answered by
0
Answer:
7 , 18
Step-by-step explanation:
Given x + (1/x) = 3
therefore find x² + (1/x²) [ using formula a²+b² = (a+b)² - 2ab , we get]
= [x + (1/x)]² - 2(x)(1/x)
= 3²-2 = 9-2
= 7
therefore find x³ + (1/x³) [ use formula a³+b³ = (a+b)³- 3ab(a+b) ]
= [x + (1/x)]³ - 3(x)(1/x)(x +1/x)
= 3³ - 3(1)3
= 27-9
= 18
Similar questions