jl
First we need to get a picture in our heads:|dw:1375144063850:dw| I arbitrarily chose that the radius of the circle is one.
\[\csc x=\frac{ 1 }{ \cos x }=9 \rightarrow \cos x=\frac{ 1 }{ 9 }\]So:|dw:1375144288301:dw|Here I think you need to use some Half angle dormulas.
First half-angle formula: \[\cos x=2 \cos ^{2} \frac{ x }{ 2 }-1 \rightarrow \cos \frac{ x }{ 2 }=\sqrt{\frac{ \cos x +1 }{ 2 }}=\sqrt{\frac{ \frac{ 1 }{ 9 }+1 }{ 2 }}\]Now you do the same with this formulas: \[cosx=1-2 \sin ^{2} \frac{ x }{ 2 }\]For the last one, just divide the sin and the cos
Well, I had that doubt because you are right. The problem is that the initial condition is cscx=9, not -9
Well, acording to my equation, cos should be sqrt 10/18
Oh yeah you are right
You just need to apply the half.angle formula's I gave for what you got for cosx
jhalt post your work for cos x/2 (I assume you already have sin x/2 ?)
yes, I understand... but what did you do ?
isn't cos x = - sqrt(80)/9 ?
yes you are doing 1 + cos(x) as the first step so 1 + - sqrt(80)/9
looks good
tan is sin / cos
yes, that all is correct
Join our real-time social learning platform and learn together with your friends!