Question

If a/b + b/a = -1, then a³-b³ =
A. 1
B. -1
C. 1/2
D. 0

Answer 1

Given : a/b + b/a = - 1.

[Mistake in the question]

To find : value of a³ - b³  

 

Solution :  

We have ,a/b + b/a = -1

On taking LCM of the denominators :  

= (a × a + b × b)/ab = - 1

= - ab = a² + b²

= a² + b² + ab = 0 …………..(1)

We know that , a³ – b³ = (a – b)(a² + b² + ab)

a³ – b³ = (a – b)(0)

[From eq 1]

a³ – b³ = 0

Hence the value of a³ – b³ is 0.

 

Among the given options option (D) 0  is correct.

HOPE THIS ANSWER WILL HELP YOU…..

 

Some questions of this chapter :

If x³ + 1/x³ =110, then x +1/x = ?

A. 5

B. 10

C. 15

D. none of these

https://brainly.in/question/15897827

 

If x+ 1/x =3, then x⁶ + 1/x⁶ =

A. 927

B. 414

C. 364

D. 322

https://brainly.in/question/15897825