JEE Advanced2010MathematicsApplication of DerivativesActual
Let f be a function defined on R (the set of all real numbers) such that f^ (x)=2010(x-2009)(x-2010)^2(x-2011)^3(x-2012)^4 , for all x R . If g is a function defined on R with values in the interval (0, ) such that f(x)= (g(x)) , for all x R , then the number of points in R at which g has a local maximum is
Correct answer
1
Step-by-step solution
Let g(x)=e^ f(x) , x R g^ (x)=e^ f(x) f^ (x) f^ (x) changes its sign from positive to negative in the neighbourhood of x=2009 f(x) has local maxima at x=2009 So, the number of local maximum is one.