For any two real numbers a and b, we define a R b if and only if sin2(a) + cos2(b) = 1. The relation R is
reflexive but not symmetric
symmetric but not transitive
transitive but not reflexive
an equivalence relation
The total number of injections (one-one into mappings) from {a1, a2, a3, a4} to {b1, b2, b3, b4, b5, b6, b7} is
400
420
800
840
Let IR be the set of real numbers and f : IR ➔ IR be such that for all x, y ∈ IR, . Prove that f is a constant function.
Let R be the set of real numbers and the mapping f : R R and g : R R be defined by f(x) = 5 - x2 and g(x) =3 - 4, then the value of (fog) (- 1) is
- 44
- 54
- 32
- 64
A = {1, 2, 3, 4}, B = {1, 2, 3, 4, 5, 6} are two sets, and function f : Aa B is defined by f(x) = x + 2 x A, then the function!
bijective
onto
one-one
many-one
A mapping from N to N is defined as follows f : N N f(n) = (n + 5)2, n N
(N is the set of natural numbers). Then,
f is not one to one
f is onto
f is both one to one and onto
f is one to one but not onto
D.
f is one to one but not onto
Given, f : N N, f (n) = (n + 5)2
For one to one
f is one to one.
When we put n = 1, 2, 3, 4, ... , we will get f (1) = 36, f (2) = 49, f(3) = 64, f(4) = 81, ...
Here, we see that we do not get any pre-images of 1, 2, 3 etc.
Hence, f is not onto