Professor

- 2
- 3
- -3
- 1

Asked by Anurag Mishra on 1st August 2015 in Maths.

4 Answers

Professor

**Answer: (2) 3
Explanation:-
**a

Both side divide by a,

a

a + 1/a + 1

On squaring of both sides,

(a + 1/a)

a

a

a

On cubing of both sides,

(a

(a

a

a

a

(a

a

Hence, the answer is (2) 3.

Answered by Anurag Mishra on 1st August 2015..

Default

Default

**a ^{2} +1 = a**

**a ^{2} –a +1 =0**

**multiply by (a+1) on both side**

**(a+1)( a ^{2} –a +1) =0**

**a ^{3} + 1^{3} = 0 ( Since a^{3} + 1^{3} = (a+1)( a^{2} –a +1)**

**a ^{3} = -1**

**Now put the value of a ^{3} in given expression**

**a ^{12} + a^{6} +1= (-1)^{4} + (-1)^{2} + 1 =1+1+1 = 3**

Answered by ramsingh on 12th December 2016..

Default

**a ^{2} +1 = a**

**a ^{2} –a +1 =0**

**multiply by (a+1) on both side**

**(a+1)( a ^{2} –a +1) =0**

**a ^{3} + 1^{3} = 0 ( Since a^{3} + 1^{3} = (a+1)( a^{2} –a +1)**

**a ^{3} = -1**

**Now put the value of a ^{3} in given expression**

**a ^{12} + a^{6} +1= (-1)^{4} + (-1)^{2} + 1 =1+1+1 = 3**

Answered by ramsingh on 12th December 2016..