Plot equation using GUI

I want to make an equation solver.I would like to plot that equation(explicit and implicit).

Then i would like to show the intersecting point of that curve and x axis.

How to do that?
    function varargout = calculator(varargin)
% CALCULATOR MATLAB code for calculator.fig
%      CALCULATOR, by itself, creates a new CALCULATOR or raises the existing
%      singleton*.
%
%      H = CALCULATOR returns the handle to a new CALCULATOR or the handle to
%      the existing singleton*.
%
%      CALCULATOR('CALLBACK',hObject,eventData,handles,...) calls the local
%      function named CALLBACK in CALCULATOR.M with the given input arguments.
%
%      CALCULATOR('Property','Value',...) creates a new CALCULATOR or raises the
%      existing singleton*.  Starting from the left, property value pairs are
%      applied to the GUI before calculator_OpeningFcn gets called.  An
%      unrecognized property name or invalid value makes property application
%      stop.  All inputs are passed to calculator_OpeningFcn via varargin.
%
%      *See GUI Options on GUIDE's Tools menu.  Choose "GUI allows only one
%      instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES

% Edit the above text to modify the response to help calculator

% Last Modified by GUIDE v2.5 18-Apr-2021 19:51:46

% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @calculator_OpeningFcn, ...
                   'gui_OutputFcn',  @calculator_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT


% --- Executes just before calculator is made visible.
function calculator_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
% varargin   command line arguments to calculator (see VARARGIN)

% Choose default command line output for calculator
handles.output = hObject;

% Update handles structure
guidata(hObject, handles);

% UIWAIT makes calculator wait for user response (see UIRESUME)
% uiwait(handles.figure1);


% --- Outputs from this function are returned to the command line.
function varargout = calculator_OutputFcn(hObject, eventdata, handles) 
% varargout  cell array for returning output args (see VARARGOUT);
% hObject    handle to figure
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Get default command line output from handles structure
varargout{1} = handles.output;



function screen_Callback(hObject, eventdata, handles)
% hObject    handle to screen (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of screen as text
%        str2double(get(hObject,'String')) returns contents of screen as a double


% --- Executes during object creation, after setting all properties.
function screen_CreateFcn(hObject, eventdata, handles)
% hObject    handle to screen (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows.
%       See ISPC and COMPUTER.
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end


% --- Executes on button press in number8.
function number8_Callback(hObject, eventdata, handles)
% hObject    handle to number8 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'8'));


% --- Executes on button press in number7.
function number7_Callback(hObject, eventdata, handles)
% hObject    handle to number7 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'7'));


% --- Executes on button press in number9.
function number9_Callback(hObject, eventdata, handles)
% hObject    handle to number9 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'9'));


% --- Executes on button press in number5.
function number5_Callback(hObject, eventdata, handles)
% hObject    handle to number5 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'5'));


% --- Executes on button press in number4.
function number4_Callback(hObject, eventdata, handles)
% hObject    handle to number4 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'4'));


% --- Executes on button press in number6.
function number6_Callback(hObject, eventdata, handles)
% hObject    handle to number6 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'6'));

% --- Executes on button press in number2.
function number2_Callback(hObject, eventdata, handles)
% hObject    handle to number2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'2'));


% --- Executes on button press in number1.
function number1_Callback(hObject, eventdata, handles)
% hObject    handle to number1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'1'));


% --- Executes on button press in number3.
function number3_Callback(hObject, eventdata, handles)
% hObject    handle to number3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'3'));


% --- Executes on button press in number0.
function number0_Callback(hObject, eventdata, handles)
% hObject    handle to number0 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'0'));


% --- Executes on button press in dot.
function dot_Callback(hObject, eventdata, handles)
% hObject    handle to dot (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'.'));


% --- Executes on button press in numberpi.
function numberpi_Callback(hObject, eventdata, handles)
% hObject    handle to numberpi (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'pi'));


% --- Executes on button press in root.
function root_Callback(hObject, eventdata, handles)
% hObject    handle to root (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


% --- Executes on button press in square.
function square_Callback(hObject, eventdata, handles)
% hObject    handle to square (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)


% --- Executes on button press in equal.
function equal_Callback(hObject, eventdata, handles)
% hObject    handle to equal (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global A B C D Selector
switch Selector
    case 1
        A = A/str2num(get(handles.screen,'string'));
        set(handles.screen,'string',num2str(A));
    case 2
        B = B*str2num(get(handles.screen,'string'));
        set(handles.screen,'string',num2str(B));
    case 3
        C = C-str2num(get(handles.screen,'string'));
        set(handles.screen,'string',num2str(C));
    case 4
        D = D+str2num(get(handles.screen,'string'));
        set(handles.screen,'string',num2str(D));
end      
        

% --- Executes on button press in ccc.
function ccc_Callback(hObject, eventdata, handles)
% hObject    handle to ccc (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

set(handles.screen,'string',' ');


% --- Executes on button press in division.
function division_Callback(hObject, eventdata, handles)
% hObject    handle to division (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global A Selector
A = str2num(get(handles.screen,'string'));
Selector = 1;
set(handles.screen,'string',' ');



% --- Executes on button press in multiply.
function multiply_Callback(hObject, eventdata, handles)
% hObject    handle to multiply (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global B Selector
B = str2num(get(handles.screen,'string'));
Selector = 2;
set(handles.screen,'string',' ');


% --- Executes on button press in minus.
function minus_Callback(hObject, eventdata, handles)
% hObject    handle to minus (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global C Selector
C = str2num(get(handles.screen,'string'));
Selector = 3;
set(handles.screen,'string',' ');


% --- Executes on button press in plus.
function plus_Callback(hObject, eventdata, handles)
% hObject    handle to plus (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global D Selector
D = str2num(get(handles.screen,'string'));
Selector = 4;
set(handles.screen,'string',' ');


% --- Executes on button press in valuex.
function valuex_Callback(hObject, eventdata, handles)
% hObject    handle to valuex (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'x'));




% --- Executes on button press in valuey.
function valuey_Callback(hObject, eventdata, handles)
% hObject    handle to valuey (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
s=get(handles.screen,'string');
set(handles.screen,'string',strcat(s,'y'));




% --- Executes on button press in simulat.
function simulat_Callback(hObject, eventdata, handles)
% hObject    handle to simulat (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)