But you need to understand Newton Method.
Could someone help please.
I don't know how to solve this
I know the answer is approx 1.8536 (Wolfram alpha)
and I know what the graph looks like (Desmos)
I have played with it but I have not had any success.
Newton's method, also known as the Newton-Raphson method, is probably the first method that would spring to mind. For this example though a simple fixed point iteration will suffice.
Rewrite the equation as
from which form the iterative equation
A simple sketch graph shows that the root is somewhere around , so taking this to be our starting value successive substitution gets us the sequence
1.84164, 1.85463, 1.85353, 1.85362, 1.8536237 etc.