Solve ((x+5)^5) + ((x-1)^5) >= 244 ?

1 Answer
May 26, 2018

# x ge -1.7045... #

Explanation:

#f(x) = (x+5)^5 + (x-1)^5 -244#

#f# necessarily has at least one real zero, being of odd degree.

#f'(x)=5(x+5)^4 + 5(x-1)^4#

We note the derivative is always positive, so #f# is monotonically increasing. So the solution to our inequality is

#x ge r #

where #r# is the sole real zero of #f#.

There's almost certainly no closed form for #r#; Alpha gives a numerical zero #r approx -1.7045.#

# x ge -1.7045... #