Anonymous
Anonymous asked in Science & MathematicsMathematics · 10 months ago

math probelem:find x?

Attachment image

2 Answers

Relevance
  • 10 months ago

    1 / (u-1) - 1 / (u+1)

    = (u + 1 - u + 1) / (u^2 - 1)

    = 2 / (u^2 - 1)

    Let's start with u = √x

    1 / (√x-1) - 1/(√x+1) = 2 / (x - 1)

    2/(x-1) - 2/(x+1) = 2[1/(x-1) - 1/(x+1)]

    = 2 * 2/(x^2 - 1)

    = 4 / (x^2 - 1)

    4 / (x^2 - 1) - 4 / (x^2 + 1) = 8 / (x^4 - 1)

    8 / (x^4 - 1) - 8 / (x^4 + 1) = 16 / (x^8 - 1)

    16 / (x^8 - 1) = 1/5

    x^8 = 16*5 + 1

    We take only the positive root because of √x

    x = 81^(1/8) = 9^(1/4) = 3^(1/2) = 1.73205...

  • Ash
    Lv 7
    10 months ago

    Please see below solution

    Attachment image
Still have questions? Get answers by asking now.