Question

Find x in this equation:
3+2cos x= 5 sin 2x

Answer 1

I got up to something like 1.5=cos x (5sin x -1)

Answer 2

When you're done @satellite73 could you please help me with my DE problem?

Answer 3

lets try
\[5\sin(2x)-2\cos(x)-3=0\]
\[10\sin(x)\cos(x)-2\cos(x)-3=0\] hmm that doesn't seem to help

Answer 4

@MathSofiya i would love to but i really forgot the very few things i knew about ODE

Answer 5

sin (a+b) = sin a cos b - cos a sin b , right?

Answer 6

@satellite73 ?

Answer 7

It's a +
sin (a+b) = sin a cos b + cos a sin b

Answer 8

I meant -

Answer 9

(subtraction)
That is what I used in my work.

Answer 10

._.! Alright.. \[sin(a\pm b) = sina\ cosb \pm cosa \ sinb\]

Answer 11

But I still cannot figure out how to get x from\[1.5= \cos x (5 \sin x - 1)\]