Question

Show that a function f(x)=3x+2 is one to one and onto

Answer 1

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=) f(x) = 3x +2

◆here we can see that f(x) is defined for every value of x ...

domain € R

and for each value of x we get unique vales of f(x) ....

=) f(x) is one - one

_____range :-

put f(x) = y

now, y = 3x + 2

= ) x = (y-2)/3 ------(1)

from above equation we can say that for every value of y ...x is defined

so =) Range € R

therefore , Range = co-domain

hence , f(x) is onto..

so we conclude that : f(x) is one-one onto

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#Q.E.D