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Calculus help

I can't seem to be able to solve this D:

If f(x) = x^5 + x^3 + x, find f^-1(3). f^-1 being the inverse function.

September 17, 2013

9 Comments • Newest first

LiliKoby

solve for 3 = x^5 + x^3 +x. if you dont know the algebra, use wolframalpha (answer is 1 if you still dont know)

Reply September 17, 2013 - edited
Ultros0

[quote=Gregar41]Stupid algebra 1-2 kid trying to look smart.[/quote]

Now when you talk like that people aren't going to like you are they?

Reply September 17, 2013 - edited
cb000

Isn't that basically solving for 3=x^5+x^3+x? Just turn it into x^5+x^3+x-3 and find the zero.

Reply September 17, 2013 - edited
Invictinite

The answer is 1

Reply September 17, 2013 - edited
Yumtoast

More like algebra 2.

Reply September 17, 2013 - edited
Blackyoshi

[quote=nopaycheck]*that's algebra, not calculus.
Anyway to get an inverse function all you do is switch the x and y variables and solve for y again.
For your problem it would be " x = y^5 + y^3 + y "
Solve for y and plug in 3 as x like you would with any other function and there's ur answer.[/quote]

Sorry, I should've been more specific lol. I'm not sure how to approach the isolating y part. I tried factoring it out and stuff, but it got even more complicated:
x = y ( y^2 (y^ + 1) + 1 ) xD

Reply September 17, 2013 - edited
fun2killu

a lot of early calc. is algebra. good luck.

Reply September 17, 2013 - edited
Gregar41

Stupid algebra 1-2 kid trying to look smart.

Reply September 17, 2013 - edited
nopaycheck

*that's algebra, not calculus.
Anyway to get an inverse function all you do is switch the x and y variables and solve for y again.
For your problem it would be " x = y^5 + y^3 + y "
Solve for y and plug in 3 as x like you would with any other function and there's ur answer.

Reply September 17, 2013 - edited