Question 763395
find x which minimizes {{{f(x)= x-sqrt(1-x^2)}}}
f'(x) = {{{1 - (1/2)*(-2x)/sqrt(1-x^2)}}}
= {{{1 + x/sqrt(1-x^2) = 0}}}
{{{sqrt(1-x^2) + x = 0}}}
{{{x = -sqrt(1-x^2)}}}
{{{x^2 = 1-x^2}}}
{{{x = - sqrt(2)/2}}}