Question

sin x cos x - 2 cos x = 0

how would you solve that? what identities?

Answer 1

sin x cos x - 2 cos x = 0
cosx (sinx -2) =0
either
cos x =0 or sinx -2 =0
but sinx -2 =0 means sinx =2 wihch is not possible
so
cosx =0
so x =(2n+1) *(pi/2) n being integer

Answer 2

the solution would be 90 degrees right?

Answer 3

and 3pi/2

Answer 4

because cos is 0 at that point too right?

Answer 5

yup
you put other integral values for n you may get 270 ,450 .... and so on

Answer 6

alright cool thanks

Answer 7

welcome...