in Geogebra.]]>

I am thinking about making another one of these.

]]>Why don't you zoom in? That way you have "more" space to put more points. I think you can get a 100 even.

]]>Another one came up. We need the area of the red shape in the first picture.

1) Input f(x) = x+1. A straight line will be drawn.

2) Input g(x)=6x-x^2-3. A parabola will be drawn.

3) Get the points of intersection of the two equations using the intersection tool. The points will be labelled A,B.

4) Go into options, labelling and check no new objects. Also hide the labels of A and B.

5) Use the polygon tool and carefully click on A and then place as many points as you on that curve until you finish at B and then click A to complete the polygon. I managed 19 points on the curve. See the second picture.

6) Read off the value of poly1, I got 4.48347. That is a good estimate of the area of the red area.

Now geogebra has an incredible command that does this for us.

7) Input integral[f,g,x(A),x(B)] and immediately our area is hsaded darker and in the algebra pane you will see a new value of 4.5. That is the exact answer. I am quite close. How did you do?

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