[SPM Add Maths Integration] Chapter 3: integration

Can someone help me please :pray::pray::pray::pleading_face::pleading_face::sob: I donโ€™t know why Iโ€™m ending up with wrong answer even I use calculator โ€ฆ Iโ€™m not confident although every time I got same answer but the textbook answer is wrong โ€ฆ The method is correct but answer only wrong โ€ฆ So please help me friends :sob::pray::pray::pray:

Whatโ€™s the question? You should at least post the question so that people can know what is going on?

And this is the question โ€ฆ

Question

In the diagram on the right, the curve y^{2}=4-x and the straight line y=x-2 intersect at two points, A and B.
Find
(a) the coordinates of A,
(b) the coordinates of B,
(c) the generated volume, in terms of \pi, when the enclosed shaded region by the curve y^{2}=4-x and the straight line y=x-2 is rotated through 360^{\circ} about the y-axis.
image

Answer

Hi Dhaksheina, I think you made a sign error:
It should be:
y^2=4-x and x=4-y^2

Here is my working for your reference:

Note that I used the volume of a cone formula instead of integrating the straight line as it is faster, but your method works fine too! :slight_smile:
image

Do let me know if my answer differs from the textbook and feel free to clarify if you have any doubts! :smiley: