# How to find how many intersections in a graph?

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Philip Chen on 22 Oct 2021
Commented: KSSV on 25 Oct 2021
I made this graph that focuses only on the first quadrant. I am supposed to display the number of intersections between the circle and the tangent and negative cotangent graphs, and I am stuck at this very point. Any help here is deeply appreciated!
%Constant
r=4
dx=0.01
%Ranges
x1 = 0:pi/100:5*pi/2-dx;
x2 = 0:pi/100:5*pi/2-0.01;
x3 = 0:pi/100:5*pi/2-0.01;
%Function
tanFunc=@(x) tan(x)
cotFunc=@(x1) -cot(x1)
circleFunc = @(x3) sqrt(16-x3.^2);
diff_fun = @(v) circleFunc(x2) - tanFunc(x3);
%Plotting
y1=tanFunc(x1)
hold on
y2=cotFunc(x2)
hold on
y3=circleFunc(x3)
%plot(x2, y2)
plot(x1, y1, x2, y2, x3, y3)
set(gca,'XLim',[0 r]);
set(gca,'YLim',[0 r]);

KSSV on 22 Oct 2021
Edited: KSSV on 22 Oct 2021
Refer this function:
##### 2 CommentsShowHide 1 older comment
KSSV on 25 Oct 2021
You caclulate the dimensions of the output from interX. I guess output of intersetion points is a row matrix.
N = size(P,2)
Number of columns should give you number of intrsection points.