× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
r
4
Home Q & A Board Science-Related Homework Help Mathematics
New Topic  
toonoo toonoo
wrote...
Posts: 6
Rep: 0 0
10 years ago
Hello, can someone help me find the inverse function of x^3 + x. I know how to find inverse functions but I don't know what to do when it seems impossible to isolate x. Any help will be appreciated.
Read 338 times
2 Replies

Related Topics

Replies
wrote...
#1
10 years ago
f(x) = x^3 + x = y
x = y^3 + y
Unfortunately, there is no "Cubic Formula" analogous to the Quadratic Formula, which can easily solve a general cubic equation.
wrote...
#2
10 years ago
solve(x = y^3+y, y)

y1 = (1/6)*(108*x+12*sqrt(12+81*x^2))^(1/3)-2/(108*x+12*sqrt(12+81*x^2))^(1/3),

y2 =  - (1/12)*(108*x+12*sqrt(12+81*x^2))^(1/3)+1/(108*x+12*sqrt(12+81*x^2))^(1/3)+(1/2*i)*sqrt(3)*((1/6)*(108*x+12*sqrt(12+81*x^2))^(1/3)+2/(108*x+12*sqrt(12+81*x^2))^(1/3)),

y3 = - (1/12)*(108*x+12*sqrt(12+81*x^2))^(1/3)+1/(108*x+12*sqrt(12+81*x^2))^(1/3)-(1/2*i)*sqrt(3)*((1/6)*(108*x+12*sqrt(12+81*x^2))^(1/3)+2/(108*x+12*sqrt(12+81*x^2))^(1/3))

Read carefully the solution. You have one real solution and two complex solutions!
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1287 People Browsing
 115 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Related Images
  
 185
  
 219
  
 197
Your Opinion
Who's your favorite biologist?
Votes: 586
Previous poll results: Which industry do you think artificial intelligence (AI) will impact the most?