Friends kindly enlighten me on the following aspects:

Is 3 + Sq. root of 2 - irrational?

Whether irrational roots occur in pair?

As an example (3+ Sq. root of 2) and (3 - Sq. root of 2)

Hope I have made myself clear.

Thanks.

Printable View

- January 2nd 2012, 09:55 AMarangu1508about nature of roots
Friends kindly enlighten me on the following aspects:

Is 3 + Sq. root of 2 - irrational?

Whether irrational roots occur in pair?

As an example (3+ Sq. root of 2) and (3 - Sq. root of 2)

Hope I have made myself clear.

Thanks. - January 2nd 2012, 10:06 AMPlatoRe: about nature of roots
- January 2nd 2012, 10:15 AMarangu1508Re: about nature of roots
Thank you Mr. Plato. Very useful. So the coefficients of a quadratic should be rational for the roots to be (irrational) pair.

- January 2nd 2012, 01:21 PMHallsofIvyRe: about nature of roots
**If**all coefficents of a quadratic equation are rational,**then**the all irrational roots appear in "conjugate pairs". Your statement, "So the coefficients of a quadratic should be rational for the roots to be (irrational) pair", however, is**not**necessarily true. An obvious example is which has irrational coefficients but "irrational pair" roots, . - January 2nd 2012, 06:04 PMokokjaeRe: about nature of roots
Suppose

**j**is any rational number, in this case 3. I am a math beginner, but since**j**+ any rational number is equal to a rational number [**j**+ rational number = rational number], 3 + any rational number = a rational number. I know obvious. Now comes the challenge, is 3 + an irrational number equal to an irrational number? When we found out that 3 + any rational number = a rational number, so 3 + any irrational number can't be a rational number or**j**+ irrational number does not equal a rational number. Therefore,**j**+ an irrational number must be irrational also.