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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE General & Further Mathematics => Topic started by: iloveschool on November 08, 2011, 12:26:21 pm

Title: last question on trigonometry
Post by: iloveschool on November 08, 2011, 12:26:21 pm

for the last question of trigonometry, bii), can somebody please tell me the equation to get 438m^3?
and also what was the question asking to be done, because im unsure about this one

thanks :)

Title: Re: last question on trigonometry
Post by: some dude on November 08, 2011, 04:57:42 pm

this is what i did.
x/(x+18) =2\3.5
x=24
therfeore, h=24+18 = 42m

then for the volume:
1/3*pi*3.5^2*42-(1/3*pi*2^2*24)
or... you can use scale factor but i just did it that way to make sure...
1/3*pi*3.5^2*42=A
A-(2/3.5)^3*A
which will give you the same answer

Title: Re: last question on trigonometry
Post by: iloveschool on November 08, 2011, 05:40:47 pm

so the question didnt ask for the volume of the whole thing? what i mean is did the question ask for the volume of the whole 42 metre height? i forgot what the object was sorry lol

Title: Re: last question on trigonometry
Post by: Natters on November 08, 2011, 05:57:18 pm

didnt it want the volume of the 18 metre half cone?