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Maths Question URGENT

Hi guys,
I am slightly confused by this question as I'm not sure why you would need to subtract the integral from the area of the rectangle. Since the area is negative, I thought the answer would be +24. Could you please clarify?
(edited 1 year ago)
Original post by Nithu05
Hi guys,
I am slightly confused by this question as I'm not sure why you would need to subtract the integral from the area of the rectangle. Since the area is negative, I thought the answer would be +24. Could you please clarify?

The 24 is the area between the curve and the x-axis (positive).
So to get R, subtract 24 from the area of bounding rectangle (60).
Reply 2
Original post by mqb2766
The 24 is the area between the curve and the x-axis (positive).
So to get R, subtract 24 from the area of bounding rectangle (60).


I'm not sure I understand. Why isn't the area between the curve and the x-axis, the area of region R?
Original post by Nithu05
I'm not sure I understand. Why isn't the area between the curve and the x-axis, the area of region R?


Draw vertical lines up, starting from the x-axis and finishing at the curve. That region is what youre finding the area of when you perform integration. R lies on the other side of the curve.
(edited 1 year ago)
Reply 4
Original post by mqb2766
Draw vertical lines up, starting from the x-axis and finishing at the curve. That region is what youre finding the area of when you perform integration. R lies on the other side of the curve.


Thank you! So could you please explain what this represents because I thought integrating was the area underneath the graph but clearly this is above the graph and below the x-axis?
Original post by Nithu05
Thank you! So could you please explain what this represents because I thought integrating was the area underneath the graph but clearly this is above the graph and below the x-axis?


Integration is the signed area between the x-axis and the curve. In this posted example the vertical lines start at the x-axis and go down so the function values and hence the signed area is negative.

Talking about the area under the graph is loose, and not correct in this case.
(edited 1 year ago)
Reply 6
Original post by mqb2766
Integration is the signed area between the x-axis and the curve. In this posted example the vertical lines start at the x-axis and go down so the function values and hence the signed area is negative.

Talking about the area under the graph is loose, and not correct in this case.


Thank you so much for the clarification!

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