Question 53060
{{{sqrt(x + 1) + sqrt(x - 1) = sqrt(2x + 1)}}}
{{{2*sqrt(x + 1)*sqrt(x - 1) + (x + 1) + (x - 1) = 2x + 1}}}
{{{sqrt(x + 1)*sqrt(x - 1) = 1/2}}}
{{{(x + 1)(x - 1) = 1/4}}}
{{{x^2 = 5/4}}}
{{{x = sqrt(5)/2}}} and {{{x = -sqrt(5)/2}}} ~> won't work because you can not take the square root of a negative value
Answer: {{{sqrt(5)/2}}}
{{{graph(300,300,-5,5,-5,5,sqrt(x + 1) + sqrt(x - 1),sqrt(2x + 1))}}}