KVPY2017MathematicsFunctions
Let f ( x )= (1+ x ² ) and A be a constant such that | f ( x )- f ( y )| | x - y | A for all x , y real and x y . Then the least possible value of A is
Options
- Aequal to 1
- Bbigger than 1 but less than 2
- Cbigger than 0 but less than 1
- Dbigger than 2
Correct answer
A. equal to 1
Step-by-step solution
f(x)= 2 x 1+x² Range of 2 x 1+x² [-1,1] |f(x)-f(y)| |x-y| A means maximum value of | f ( x )- f ( y )| | x - y | is always less than or equal to A . So, least value of A is 1