Q&A - Ask Doubts and Get Answers
Q

Tell me? - Sets, Relations and Functions - JEE Main-10

What is the value of identity element e so that a*e=a=e*a, where a*b=a^{2}+b^{2}?

  • Option 1)

    a

  • Option 2)

    \sqrt{a^{2}-a}

  • Option 3)

    \sqrt{a-a^{2}}

  • Option 4)

    2a

 
Answers (1)
111 Views

As we learnt

 

Invertible Binary operation -

 

a*b = e = b*a 

- wherein

e be the identity element for the binary operation * on A and a,b \epsilonA

 

 a^{2}+l^{2}= a= l^{2}+a^{2}

\Rightarrow l^{2}= a\left ( 1-a \right )= a\left ( 1-a \right )

\Rightarrow l=\pm \sqrt{a\left ( 1-a \right )}

 


Option 1)

a

Option 2)

\sqrt{a^{2}-a}

Option 3)

\sqrt{a-a^{2}}

Option 4)

2a

Exams
Articles
Questions