Need help trigonometric equations (1 Viewer)

[1xcv3we]

Hi everyone,

The problem I have is find all solutions for:

sin(x)tan(x)=sin(x) on the interval -pi<=x<=pi

I suck at solving these kinds of problems in general. If anyone knows of some great websites or videos which have a good explaination for solving trig functions please post them here.

Cheers.

 

[Shadowdude]

Go from there, it should be easy.

 

[Shadowdude]

Sinxtanx=sinx
Sinxtanx-sinx=0
Sinx(tanx-1)=0
Therefore sinx=0 and tanx=1
X = pi/4 and 3pi/4

did you consider the interval in which solutions must be given: ?

 

[1xcv3we]

Yeah thanks I got it. I solved for sin(x)=0 and tan(x)=1 and got the 5 solutions -pi, 0, pi, pi/4 and 3pi/4.

 

[Timske]

did you consider the interval in which solutions must be given: ?

nope

 

[Frostkruncher]

Yeah thanks I got it. I solved for sin(x)=0 and tan(x)=1 and got the 5 solutions -pi, 0, pi, pi/4 and 3pi/4.

isnt it -3pi/4?

 

[bleakarcher]

^ yes.

 

[1xcv3we]

isnt it -3pi/4?

Yes, my apologies, I forgot to write the minus sign.