Question

solve sin2x=cosx for exact solutions. 0<=x<=2pi

Answer 1

0<=x<=2 pi

Answer 2

Well, what's an expression for sin 2x ?

Answer 3

2sinxcosx

Answer 4

Right. So if
2 sin x . cos x = cos x
we can reduce that to

sin x = 1/2

Now you just need to find x in the given range for which this is true.

Answer 5

\[2\cos(x)\sin(x)-\cos(x)=0 =>\cos(x)(2\sin(x)-1)=0\]

Answer 6

\[\cos(x) =0 \text{ or} \sin(x)=\frac{1}{2}\]

Answer 7

true ... was getting there, but he's gone, so I'm glad we've got it on the record.

Answer 8

lol yes

Answer 9

*sigh* hate it when they don't stay and engage with you.

Answer 10

i'm sorry, my computer shut down on me. but thanks a lot for the help

Answer 11

ok