Question

How to integrate this with respect to y? 2(x*cosx+sinx)

Answer 1

@hartnn @amistre64

Answer 2

\[\int 2x\cos x +\sin xdy\]?
if so, treat x as a constant

Answer 3

Isn't it 2*sinx instead of sin x?

Answer 4

yeah sorry

Answer 5

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCAQFjAA&url=http%3A%2F%2Fwww.bucks.edu%2Fmedia%2Fbcccmedialibrary%2Ftutoring%2Fdocuments%2Fmath%2FFirstOrderDiffEq.pdf&ei=GVk9VNv1GYaoyAS5hYDIBg&usg=AFQjCNFJyt32SYozILX3bmWaNZ10oULX9w&bvm=bv.77412846,d.aWw

Answer 6

there

Answer 7

So the answer is (2x*cosx+2*sinx)y, right?

Answer 8

@Walker_Stalker_Con please explain things rather than just posting links.

Answer 9

did that help

Answer 10

+c
yes

Answer 11

Because my book says (2x*cosx+2sinx)(y*siny+cosy).

Answer 12

So the book is wrong?

Answer 13

i think we are missing some information then...

Answer 14

ya just kidding your welcome

Answer 15

how exactly is your problem stated?
is there some missing context perhaps?

Answer 16

sorry my brother did that

Answer 17

post the original question

Answer 18

Find the function M such that M(x, y)dx+2xy*sinx*cosy*dy=0 is exact.

Answer 19

he is on Diff. eq. topic., i guess

Answer 20

because without more context, you just treat all x terms as constant, for example
http://www.wolframalpha.com/input/?i=integral%20sinx%20dy&t=crmtb01

Answer 21

my question

Answer 22

ah that changes things

Answer 23

hay u guys are very good at math is it ok if after this question if you can help me with one or two

Answer 24

M_y = N_x

2xy*sinx*cosy*dy

differentiate w.r.t x
then integrate w.r.t y

have you done that ?

Answer 25

i just metald some one

Answer 26

M_y = N_x

N= 2xy*sinx*cosy

differentiate w.r.t x, gives you N_x = M_y
then integrate w.r.t y, gives you M

have you done that ?

Answer 27

That's what I did, @hartnn . I got Nx=2(xcosx+sinx) and My=2(xcosx+sinx) and I'm trying to integrate My with respect to y.

Answer 28

hay u guys are pretty very good at math is it ok if after this question if you can help me with one or two

Answer 29

smart

Answer 30

not preety

Answer 31

N= 2xy*sinx*cosy

N_x = 2y cos y (sin x + x cos x)

Answer 32

while differentiating w.r.t. x,
the terms,
2,y and cos y are constants

Answer 33

I see where my mistakes are at. So I got My=2y*cos(y)*(sinx+xcosx). Now I need to integrate My with respect to y.

Answer 34

Bill and Ron build towers using blocks. The expression 4b + 2 represents the number of blocks Bill uses. The expression 8b – 5 represents the number of blocks Ron uses.



Complete the expression to represent the total number of blocks Bill and Ron use.



b −

Answer 35

yes
and treat, 2(sinx+xcosx) as constant

so u just integrate
ycos y

Answer 36

How do I integrate ycosy?

Answer 37

integration by parts

Answer 38

Walker, please ask your question in a new post, not here in replies,
Paste your question in "Ask a question..." tab on upper left side and then click "Post"
Thanks.

Answer 39

then will u help me

Answer 40

if so it will be under metal

Answer 41

Thank you so much, @hartnn !

Answer 42

welcome ^_^

Answer 43

:)