Question

substitution: the integral of cos3xdx, u=3x

Answer 1

cosu du/3

Answer 2

\[du=3 d\[\frac{1}{3}\int\limits_{}^{}\cos(u) du=\frac{1}{3}\sin(u)+C\]x\]

Answer 3

-sinu/3+c

Answer 4

not negative
derivative of sinu is cosu

Answer 5

u = 3x, du = 3dx \[\int(cos(3x)dx=\frac{1}{3}\int cos(u)u =\frac{1}{3}sin(u)=\frac{1}{3}sin(3x)\]

Answer 6

ohh sorry

Answer 7

=1/3*sin(3x)+C

Answer 8

oh yeah! +C

Answer 9

satellite your answer was so far off without that C

Answer 10

lol

Answer 11

ok so who's right?

Answer 12

obviously me

Answer 13

remember, i'm the one that doesn't know what's going on :]

Answer 14

oh, right obviouslyyy. silly me.