Question

im having trouble integrating the double iterated integral
R= [0,3] X [0,rad(9-y^2)]

and the function inside the integral is "y dy dx"

Answer 1

\[\int\limits_{0}^{3}\int\limits_{0}^{\sqrt{9-7^{2}}} y dy dx\]
thats the integral

Answer 2

something's not right with either your limits or your order of integration...

Answer 3

sorry your right.... its y dx dy

Answer 4

if you're integrating in 'dy' .. your limits will be functions of x

Answer 5

ok

Answer 6

that works...

Answer 7

integral of ydx is yx +C

Answer 8

ive tried u sub...and integration by parts. but i just cant get the answer....

Answer 9

still something weird about it though... shouldn't be written like that...

Answer 10

the problem just says.... evaluate the iterated integral

Answer 11

k

Answer 12

they're writing it weird to try and throw you off I guess...

Answer 13

anyway... plug in the limits on 'x' ... ( 0 ... srt(9-y^2) )
and then evaluate with respect to dy

Answer 14

but then what? dont we need to simplifly

Answer 15

so (y*sqrt(9-y^2) + C) dy

Answer 16

you can use u sub.s ...

Answer 17

9-y^2 = u
-2y dy = du
y dy = -du/2

Answer 18

yes but then we need to plug in 3 into \[\sqrt{9-3^{2}}\] wich equals 0 in the rad

Answer 19

so?

Answer 20

ends up canceling everything out.... and the answer is supposed to be 3

Answer 21

...

Answer 22

lower limit?

Answer 23

is 0

Answer 24

omg....

Answer 25

ive done this problem like no lie 10 times and i never pluged in the lower limit = 0 giving me the right answer 9

Answer 26

thank you so much for letting me realize this. how to i give a medal??

Answer 27

click 'best response'