If a2+9/a2=31,what is the value of a-3/a
Answers
Answered by
113
a²+9/a²=31 (i)
Following identity
(a+b)²=a²+b²+2ab
putting(i)
(a-3/a)²=a²+9/a²+2(a)(-3/a)
(a-3/a)²=31+(-6)
(a-3/a)²=25
(a-3/a)=5
Following identity
(a+b)²=a²+b²+2ab
putting(i)
(a-3/a)²=a²+9/a²+2(a)(-3/a)
(a-3/a)²=31+(-6)
(a-3/a)²=25
(a-3/a)=5
Answered by
5
a-3/a = 5
Step-by-step explanation:
(a -3/a) ^2 = a2 - 2 × a × 3/a + (3/a)
=( a+b)2
= a2 - 2ab +b2
= a2 - 6 + 9/a2
= ( a - 3/a)2 = 25
= a - 3/a = 5
Hope it helps u!! .................
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