Maths help (1 Viewer)

[cookiesncream]

I have a trigonometry equation that I hope someone can help me solve.
Domain: 0<x<180 , including 0 and 180.
sin2x= tan x

Thanks.

 

[st1m]

ok i don't have a calculator but i give u the drill
sin2x= 2sinxcosy
2sinxcosx=sinx/cosx
2sinxcos^x=sinx
2sinxcos^2x-sinx=0
sinxcos^2x=0
then solve it...

 

[Dr. Zoidberg]

2sinxcosx = tanx

2sinxcosx = sinx/cosx

2sinx(cos x)^2 = sinx

2sinx(cosx)^2 - sinx = 0

sinx[2(cosx)^2 -1] = 0

sinx = 0

cos x = 1/root2 or -1/root2

x = 0, 180, 360, 45, 135, 225, 315

SInce 0 =< x =<180,

x=0, 180, 45, 135