I got an e-mail with your response, but it hasn't shown up here
This is what I got:
Thank you for replying back so for example the question is solve the
following equation using the solve command and check your answer with
a plot (a) x^2+3x+1=0
I put : Solve[x^2 + 3 x + 1 == 0] it gave me that : {{x -> 1/2 (-3 -
Sqrt[5])}, {x -> 1/2 (-3 + Sqrt[5])}} when I tried to plot :
plot[function[x, x^2 + 3 x + 1][x]] it gave me : plot[function[x, 1 +
3 x + x^2][x]] which is the same what I wrote so what did I do wrong ?
You need to learn some Wolfram Language syntax.
In[2]:= Solve[x^2 + 3 x + 1 == 0, x]
Out[2]= {{x -> 1/2 (-3 - Sqrt[5])}, {x -> 1/2 (-3 + Sqrt[5])}}
This is what Solve does. It gives you replacement rules.
If you just want answers, you can use Reduce. I did this, and applied N to give floating point numbers.
In[3]:= Reduce[x^2 + 3 x + 1 == 0, x] // N
Out[3]= x == -2.61803 || x == -0.381966
Your syntax for the plot function is not right. Look at the documentation:
Plot[x^2 + 3 x + 1, {x, -5, 5}]
will do what you want.
As a beginner, you might want to try free-form input.
At the start of a new line, type the = sign. You will get an orange box with an equals sign. Then type what you want in plain english. The input will go to the Wolfram servers, and it will interpret what it thinks you want nd give it to you.
Note that Mathematica will give you the correct Wolfram Language input. In this way, you can learn the system. I would recommend Cliff Hastings' (et al) new book: Hands-on Start to Wolfram Mathematica. In the book is a special code that will let you take the on-line class for free that covers part of the book.
