IIT JEE , AIEEE Forum - Mathematics , Algebra

neeraj_agarwal_1990

Suppose f(x) = (x+1)² for x

1. If g(x) is the function whose graph is reflection of f(x) with respect to line y=x, then g(x) =?

[ans:- (x+1)^-2, x>-1]

Since it is reflection in y=x,
we have to replace (y by x) and (x by y)
then g(x) =

x - 1 , x

?

neeraj_agarwal_1990

Missing objects are '>='

neeraj_agarwal_1990

Mr. Moderator....plzzz..nobody is answering my questions...no member ...no expert

kghedriu

The mistake u hav done is replacing x by y and y by x when reflected through y=x line...

neeraj_agarwal_1990

why kghedriu ,when in a function , we replace y by x and x by y,we take reflection in x=y line?
then I used its converse...?

amar.gupta

The reflection of the point (x,y) across the line y = x is the point (y,x).

so for x=1 the origional eq. gives y=4

so starting point is (1,4) the reflection will be (4,1)

so y =

x - 1 , x

4

now x=(y+1)^ -2

if you also take the reflection of the axis :

then g(x)=(x+1)^-2 for x>=1

actually you have yourself solved the problem i am not getting wht you want to ask. please clear if any doubt

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