adanne1990's question
Can someone solve these problems (calculus 2 I believe). If not then I'll try to do them myself, but it's just that im tryin to do my hw..
u want them all solved?
not me someone else does.. but im workin on my hw.. and if anyone feels like solving a couple of problems then go ahead.. adanne1990 emailed them to me askin for help.
o, ok
If it didnt say "TEST" right there on it, id be more willing to oblige ... :/
lol want me to rename the file?
and rewrite it as well ;)
sure..
lolz
here are a couple of problems..
this is the drawing ... not to scale of course
your integration for area will be from 1 to 5; and from 5 to 9 \[\int_{1}^{5}(x+1)-(2)\ dx+\int_{5}^{9}(11-x)-(2)\ dx\] if I see it right
convert the equations to inverses: y = x+1 ; x = y-1 y =11-x ; x = 11-y and integrate with respect to y from 2 to 7 \[\int_{2}^{7}(y-1)-(11-y)\ dy\]
lol ... typoes it :)
\[\int_{}^{}(y-1)-(11-y)\ dy\] .. nah its good; gonna put tha tpersonaility in a time out :)
thanks man.. mind finishin it off?
y-1-11+y = 2y-12 {S} 2y-12 dy --> (2y^2)/2 -12y; y^2 -12y area = (7)^2-12(7)-[(2)^2-12(2)] = 49 - 84 -(4-24) = -35 -(-20) = -15 just caught a fauxpaux; the point above needs to be (5,6); 5+1 = 6; 11 - 5 = 6 .. which alters the integrals a little and means this set up is errored. lets try that with y from 2 to 6 area = (6)^2-12(6)-[(2)^2-12(2)] = 36 - 72 -(4-24) = -36 -(-20) = -16 <-- this negative here tells me that I just subtracted the function in the wrong order; well, not wrong, just backwards frm normality :) ill revamp this for accuracy
A). graph is good except need the points are: \begin{array}c &(5,6)&\\ (1,2)&...&(9,2)\\ \end{array} B). \(\int_{1}^{5}(x+1)-(2)dx+\int_{5}^{9}(11-x)-(2)dx\) C). \(\int_{2}^{6}(11-y)-(y-1)dy\) D). \(F(y)=\int_{2}^{6}(11-y)-(y-1)dy\) \(=\int_{2}^{6}(11-y-y+1)dy\) \(=\int_{2}^{6}(12-2y)dy\) \(=12y-y^2\) \begin{align} Area &= 12(6)-(6)^2-(12(2)-(2)^2)\\ &=72-36-(24-4)\\ &=36-20\\ &=16 \end{align}
when we rotate about the y axis; we get a radius equal to x and a height equal to f(x); so our integration goes from 1 to 9; but becasue of the change in f(x) at 5 we need to split it up; \[2\pi\left(\int_{1}^{5}x[(x+1)-2]dx+\int_{5}^{9}x[(11-x)-2]dx\right)\]
x(x-1) = x^2 - x {S} x^2 - x dx --> x^3/3 -x^2/2 5^3/3 -5^2/2 - (1^3/3 -1^2/2) 125/3 -25/2 - 1/3 -1/2 124/3 -24/2 124(2)/6 -24(3)/6 248/6 -72/6 176/6 = 29' 1/3 x(9-x) = 9x - x^2 {S} 9x - x^2 dx --> 9x^2/2 -x^3/3 9(9)^2/2 -(9)^3/3 - (9(5)^2/2 -(5)^3/3) 729/2 -729/3 - 225/2 +125/3 504/2 -604/3 504(3)/6 -604(2)/6 1512/6 -1208/6 304/6 = 50' 2/3 50' 2/3 + 29' 1/3 --------- 79' 3/3 = 80 2pi(80) = 160pi for the volume of revolution
its best to dbl chk my work, I am prone to errors in this :)
but thats about me limit for this; good luck with it :)
hey assassin dou u have a facebook?
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