Maths Relations & Functions part 22 (Example one-one onto) CBSE class 12 Mathematics XII

Maths Relations & Functions part 22 (Example one-one onto injective surjective) CBSE class 12 Mathematics XII

[AMX]

it would be great if u prove the problems mathematically also

[gowthamm]

sir, but this method is not given in ncert solution.

[idasorublin]

Tq so much exam fear..I guess this is the only channel which explains in english...thanks a lot

[shivashishsarkar]

@RhythmicGuitarCovers

But, if you want to show that a function is one-one, you can never cite enough examples of pre-images having unique image because it will never be conclusive (because you will not be able to cover the whole domain especially if it is R or a subset of R i.e. interval). Same holds true if you want to prove that a function is onto. You will need to cover the whole co-domain and show that no such element in co-domain exists which does not have a pre-image. So, this process is not suitable I conclude. When need to prove things theoretically. But sometimes, we can use that simple method to prove many-one/non-surjective nature. What say?

[shrikanthk]

Sir as mentioned in question domain being natural how come codomain will have 2/3 as output..? It always remain natural(where natural number also a real value) in codomain, may i request clarity on this .i feel it is surjective

[rohans]

Why don't you show how to write the answers.

[tseringpashi]

Please prove it mathematically n way of jotting mathematically

[akshaykamath]

sir u explain good bt y do u write things so small, its nt visible!

[sangeethasanthosh]

sir u are marvellous and an excellent teacher