SOLUTION: Find the absolute extrema of f(x)=x^a(1-x)^b where 0</= x =/< 1 and a and b are constants, both >1 I have the derivative f'(x)=ax^(a-1)(1-x)^b-x^(a)b(1-x)^(b-1) Unsure o

Algebra ->  Graphs -> SOLUTION: Find the absolute extrema of f(x)=x^a(1-x)^b where 0</= x =/< 1 and a and b are constants, both >1 I have the derivative f'(x)=ax^(a-1)(1-x)^b-x^(a)b(1-x)^(b-1) Unsure o      Log On


   



Question 1024797: Find the absolute extrema of
f(x)=x^a(1-x)^b
where 01
I have the derivative
f'(x)=ax^(a-1)(1-x)^b-x^(a)b(1-x)^(b-1)
Unsure of where to go from this point. Thank you for the help

Answer by ikleyn(53765) About Me  (Show Source):
You can put this solution on YOUR website!
.
Find the absolute extrema of
f(x)=x^a(1-x)^b
where 01
I have the derivative
f'(x)=ax^(a-1)(1-x)^b-x^(a)b(1-x)^(b-1)
Unsure of where to go from this point. Thank you for the help
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Next step is to write an equation f'(x) = 0, which gives you this:

ax%5E%28a-1%29%281-x%29%5Eb = x%5E%28a%29b%281-x%29%5E%28b-1%29.   (1)

Now cancel both sides of (1) by the factor x%5E%28a-1%29%2A%281-x%29%5E%28b-1%29. You will get

a*(1-x) = b*x.

a - ax = bx

a = (a+b)*x,

x = a%2F%28a+%2B+b%29.   1-x = b%2F%28b%2Ba%29.

f(x) = %28a%2F%28a%2Bb%29%29%5Ea.%28b%2F%28a%2Bb%29%29%5Eb