# Math Help - Trig graphs question

1. ## Trig graphs question

So i understand trig graphs until it involves $\pi$ FOR INORMATION - where i have put < i mean equal to or less the ni just dont know how to math it on here. thanks in advance

sketch the graph of

$y=sinX$ $for 0 < X < 2\pi$

solve the equation $2sinX = -1$ for $0 < X < 2\pi$

give your answers in the form $k\pi$

2. for the first one pi= 180 degrees, therefore it is asking for a normal sine graph between 0 and 360 degrees however it wants the axis marked in radians e.g. pi=180 degrees,
2pi=360 degrees and so on.

for the second one 2sinx=-1
therefore sinx= -0.5
therefore x= 210, 330 degrees and remembering that pi=180
x= 7/6 pi or 11/6 pi
does this help??

3. ## nothing like a radians refresher lesson!

Originally Posted by hmmmm
for the first one pi= 180 degrees, therefore it is asking for a normal sine graph between 0 and 360 degrees however it wants the axis marked in radians e.g. pi=180 degrees,
2pi=360 degrees and so on.

for the second one 2sinx=-1
therefore sinx= -0.5
therefore x= 210, 330 degrees and remembering that pi=180
x= 7/6 pi or 11/6 pi
does this help??
thanks very much did help : )