JEE Advanced2007MathematicsFunctionsActual
Paragraph: If a continuous f defined on the real line R , assume positive and negative values in R , then the equation f(x)=0 has a root in R . For example, if it is known that a continuous function f on R is positive at some point and its minimum values is negative, then the equation f(x)=0 has a root in R . Consider f(x)=k e^x-x for all real x , where k is real constant. Question: For k>0 , the set of all values of
Options
- A(0, 1 e )
- B( 1 e , 1 )
- C( 1 e , )
- D(0,1)
Correct answer
A. (0, 1 e )
Step-by-step solution
For two distinct roots 1+ k 0) k < -1 k < 1 e Hence, k (0, 1 e )