Stationary points help ?
- Thread starter Oors
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Steven G
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You found two cos(x)-values where the slopes are stationary. So you are almost done! Just state the equation of those two tangent line(s), which you did. You said that the equation(s) of all the tangents lines that are stationary is y=1/2.
Where you are not being complete. There are many places where cos(x)=1, not just two places. Possibly if you solved for x you might have seen that. Are all those tangent lines y= 1/2? If yes then state why. If not, are there going to be more than 2? If yes then the statement of the problem is wrong or you made an error somewhere. If not then state that 2nd equation and be done.
Where you are not being complete. There are many places where cos(x)=1, not just two places. Possibly if you solved for x you might have seen that. Are all those tangent lines y= 1/2? If yes then state why. If not, are there going to be more than 2? If yes then the statement of the problem is wrong or you made an error somewhere. If not then state that 2nd equation and be done.
pka
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\(D_x\left(\dfrac{\cos(x)}{1+\cos^2(x)}\right)=\dfrac{\sin(x)\left(\cos^2(x)-1\right)}{\left(1+\cos^2(x)\right)^2}\) so you have done the derivative correctly: SEE HEREI have attached my working to the question I don't know how to continue part b help is very much appreciated
View attachment 17722
Let's look at the zeros of \(\sin(x)[\cos^2(x)-1]\) they are \(x=n\pi,~~n\in\mathbb{Z}\) SEE HERE