Find the points of local maxima or local minima, if any, of the following functions, using the first derivative test. Also, find the local maximum or local minimum values, as the case may be:

f(x) = (x – 5)4

f(x) = (x – 5)4


Differentiate w.r.t x


f ’(x) = 4(x – 5)3


for local maxima and minima


f ‘ (x) = 0


= 4(x – 5)3 = 0


= x – 5 = 0


x = 5


f ‘ (x) changes from –ve to + ve as passes through 5.


So, x = 5 is the point of local minima


Thus, local minima value is f(5) = 0


1