SOLUTION: Solve x - sinx = 4/5 How do I solve x?

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Question 1161022: Solve x - sinx = 4/5
How do I solve x?
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

sin%28x%29+=+4%2F5
x=sin%5E-1%284%2F5%29
x=sin%5E-1%284%2F5%29
x=0.927295218 in radians
x=53.13°

Answer by ikleyn(52887) About Me  (Show Source):
You can put this solution on YOUR website!
.

            The solution by  @MathLover1 is  INCORRECT.

            I came to bring the correct solution. 


This transcendent equation CAN NOT be solved algebraically. 


It only can be solved approximately using numerical methods.


There are specialized numerical solvers for such problems.


You can use an online (free of charge) solver at web-site

https://www.wolframalpha.com/widgets/view.jsp?id=a7d8ae4569120b5bec12e7b6e9648b86



Input the function  x-sin(x) - 4%2F5  into the solver's input window and press the "Submit" button.


In seconds, you will obtain the solution  x = 1.77851  radians,

even with the accompanied plot.


This solution is UNIQUE.

Solved.