Mathematics
24 Online
OpenStudy (anonymous):
Integral question see attached images
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
OpenStudy (anonymous):
OpenStudy (anonymous):
I'm not really sure how to do this I did the anti-derivative for both of fx then used the 1st fund thrm of calc
OpenStudy (turingtest):
just break it into two integrals
what are the bounds? where is the breaking point in the function?
OpenStudy (anonymous):
hmm and just do f(b)-f(a) for both? and add them together?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (turingtest):
what do f(a) oand f(b) represent to you?
I don't see how that way of writing things helps us...
OpenStudy (anonymous):
F(b)-F(a) b being the top value and a being the bottom value listed on the integral
OpenStudy (anonymous):
b=7 and a=-1
OpenStudy (turingtest):
but the definition of f(x) is not the same throughout
OpenStudy (anonymous):
not f(x) F as in the anti-derivative lol
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (turingtest):
I understand what you are saying, but hear me...
OpenStudy (anonymous):
Yeah so how do I deal with that lol?
OpenStudy (turingtest):
we have to treat this like two different integrands f(x) to begin with
have you heard the word "integrand" before?
OpenStudy (anonymous):
no I haven't were in calc I
OpenStudy (anonymous):
rather I am in calc 1
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (turingtest):
it's the function under the integral sign
i.e. the function we area integrating is called the "integrand"
OpenStudy (turingtest):
we are*
OpenStudy (anonymous):
ahhh
OpenStudy (turingtest):
so at what value of x does the definition of the integrand f(x) change ?
OpenStudy (anonymous):
1
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
correct?
OpenStudy (turingtest):
yes, very good!
so we have two integrals, with two different integrands....
OpenStudy (turingtest):
from x=-1 to x=1 the integrand is what?
OpenStudy (anonymous):
x^2/2?
OpenStudy (anonymous):
rather x because the integrand is what we are doing to integrate right?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (turingtest):
in\[\int f(x)dx\]the integrand is just f(x)
i.e. in \\[\int x^2dx\] the integrand is the function \(f(x)=x^2\)
OpenStudy (anonymous):
how did you get x^2?
OpenStudy (anonymous):
ohhhhh
OpenStudy (turingtest):
example only
OpenStudy (anonymous):
wow sorry half asleep
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
lol
OpenStudy (anonymous):
yeah so its x!
OpenStudy (anonymous):
for -1 to 1
OpenStudy (turingtest):
yes
OpenStudy (anonymous):
so we have that now what? Integrate get x^2/2 then what?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
do -1^2/2 - 1^2/2?
OpenStudy (anonymous):
which is 0 lol
OpenStudy (turingtest):
you are right that the answer is zero, but it should be
1^2/2 - 1^2/2
the way you wrote it would result in -1
OpenStudy (turingtest):
so the first integral is zero...
what is the second integral?
OpenStudy (anonymous):
1 to 7 the integral being ln |x|?
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
muahahahaha! thats right! thanks!!!!!
OpenStudy (turingtest):
you are welcome :)
OpenStudy (turingtest):
thank you for being a good student
OpenStudy (anonymous):
^.^