Question

\[\int \sin 3xdx\]

Answer 1

u = 3x?

Answer 2

... or some trig identity?

Answer 3

u = 3x would be easiest..

Answer 4

Let's check u = 3x
du = 3dx
dx = (1/3)du
Hmm\[{1 \over 3}\int\sin udu \]

Answer 5

learnt complex nos. ? would make it interesting but still easy ..

Answer 6

\[{-1 \over 3}\cos (u) + C\]

Answer 7

\(\int{\sin 3xdx}=\frac13\int{\sin3xd(3x)}=\frac13\int{\sin u du}=?\)

Answer 8

That was not as hard as it could be hehe