If x^2+1/x^2=7,find the value of x^3+1/x^3
Answers
Answered by
0
This is the answer.If not clear, please reply.
Attachments:
prathikdasharath:
The answer is correct but the question which u thought is wrong, i mean it is wrong
the answer is wrong
Answered by
0
Given
x^2 + 1/x^2 = 7
To Find
x^3 + 1/x^3
Solution
( x + 1/x )^2 = ( x )^2 + ( 1/x )^2 + 2 ( x ) ( 1/x )
( x + 1/x )^2 = x^2 + 1/x^2 + 2
( x + 1/x )^2 = 7 + 2
( x + 1/x )^2 = 9
( x + 1/x ) = 3
or. ( x + 1/x ) = - 3
if ( x + 1/x ) = 3
than
( x + 1/x )^3 = ( x )^3 + ( 1/x )^3 + 3 (x )( 1/x ) ( X + 1/x )
( 3 )^3 = x^3 + 1/x^3 + 3 ( 3 )
27 = x^3 + 1/x^3 + 9
x^3 + 1/x^3 = 18
if x + 1/x = - 3
than
( x + 1/x )^3 = x^3 + 1/x^3 + 3 ( x + 1/x )
( - 3 )^3 = x^3 + 1/x^3 + 3 ( - 3 )
- 27 = x^3 + 1/x^3 - 9
x^3 + 1/x^3 = - 18
x^2 + 1/x^2 = 7
To Find
x^3 + 1/x^3
Solution
( x + 1/x )^2 = ( x )^2 + ( 1/x )^2 + 2 ( x ) ( 1/x )
( x + 1/x )^2 = x^2 + 1/x^2 + 2
( x + 1/x )^2 = 7 + 2
( x + 1/x )^2 = 9
( x + 1/x ) = 3
or. ( x + 1/x ) = - 3
if ( x + 1/x ) = 3
than
( x + 1/x )^3 = ( x )^3 + ( 1/x )^3 + 3 (x )( 1/x ) ( X + 1/x )
( 3 )^3 = x^3 + 1/x^3 + 3 ( 3 )
27 = x^3 + 1/x^3 + 9
x^3 + 1/x^3 = 18
if x + 1/x = - 3
than
( x + 1/x )^3 = x^3 + 1/x^3 + 3 ( x + 1/x )
( - 3 )^3 = x^3 + 1/x^3 + 3 ( - 3 )
- 27 = x^3 + 1/x^3 - 9
x^3 + 1/x^3 = - 18
Similar questions