A very tricky Question from Cambridge University Entrance Exam | Find the Value of a=?

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  • Опубліковано 16 лис 2024

КОМЕНТАРІ • 7

  • @henrybeenh7076
    @henrybeenh7076 Місяць тому +1

    Yeah, I can do this!

  • @SidneiMV
    @SidneiMV Місяць тому +8

    3125 = 5⁵
    a + 5⁵ᵃ = 0
    5⁵ᵃ = -a
    a = -u
    5⁻⁵ᵘ = u
    -5uln5 = lnu
    (1/u)lnu = -5ln5
    (1/u)ln(1/u) = 5ln5
    1/u = 5 => u = 1/5 => *a = -1/5*

    • @moemirza1865
      @moemirza1865 Місяць тому +3

      Great solution and not complicated.

  • @radupopescu9977
    @radupopescu9977 Місяць тому

    x=-(W(5ln5))/(5ln5) also, W Lambert function is multivalued so there also other values.

  • @davidseed2939
    @davidseed2939 Місяць тому +1

    as soon as you see 3125 and calculate that it is 5^5 you know a is going to be linked to 1/5.
    a little bit of trial and error error leads to a=-1/5. Not tricky at all.

  • @潘博宇-k4l
    @潘博宇-k4l Місяць тому

    a=-5