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i am a senior high school student i need getting the X-Intercept . Because my teacher told us the answer but i can not get it right . the answer is x=√3/3

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  • $\begingroup$ see Documentation >> Solve and try Solve[2 x - Sqrt[x^2 + 1] == 0, x] $\endgroup$
    – kglr
    Commented Oct 25, 2017 at 7:46
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    $\begingroup$ Sorry i can not $\endgroup$ Commented Oct 25, 2017 at 7:53
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    $\begingroup$ Why? $\phantom{}$ $\endgroup$ Commented Oct 25, 2017 at 7:55

1 Answer 1

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Your function:

 f[x_] := 2*x - Sqrt[x^2 + 1]

You can get the x-Intercept with:

sol = x /. Solve[f[x] == 0, x] // First
(*-> 1/Sqrt[3]*)

Notice that

$\frac{\sqrt{3}}{3}=\frac{1}{\sqrt{3}}$

Plot the result:

 Plot[f[x], {x, -1, 10},Epilog -> {Red, PointSize[0.02], Point[{sol, 0}]}]

no description here

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  • $\begingroup$ I really thank you. How could you do that ?? Is it a program?? Can u tell me the name? $\endgroup$ Commented Oct 25, 2017 at 8:41
  • $\begingroup$ Since you posted in the Mathematica StackExchange I used Wolfram Mathematica $\endgroup$
    – JeRut
    Commented Oct 25, 2017 at 8:42
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    $\begingroup$ How can i use it ?? $\endgroup$ Commented Oct 25, 2017 at 8:46
  • $\begingroup$ You need to purchase a license. But since you are a student your school/university maybe already did that. $\endgroup$
    – JeRut
    Commented Oct 25, 2017 at 8:50

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