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trusev1
Group Title
Find all points (i.e. all xvalues) between 0 and 2pi where the line tangent to the graph
of y =sinx/2+cosx is horizontal
 one year ago
 one year ago
trusev1 Group Title
Find all points (i.e. all xvalues) between 0 and 2pi where the line tangent to the graph of y =sinx/2+cosx is horizontal
 one year ago
 one year ago

This Question is Open

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
Have you considered the 1st Derivative?
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
1st derivative would be (cot x) (cosx/sinx) how would I get the points from that?
 one year ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
If that is the correct 1st derivative, which I didn't check, you determine where it is zero.
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
well the derivative of sinx is cosx and the derivative of any constant is always 0 and the derivative of cosx is sinx and we know that cotx =cosx/sinx
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
I am not sure how I would determine where it would be zero..
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
horizontal tg = 0(no variation)
 one year ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
No. That will not do. You need the Quotient Rule. I get the 1st Derivative as \(\dfrac{2\cos(x)+1}{(2+\cos(x))^{2}}\). After that, simply concern yourself with the numerator being zero, unless the denominator happens to be zero in the same place.
 one year ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
This assumes your original expression was \(\dfrac{\sin(x)}{2+\cos(x)}\). Was it?
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
dw:1372217350005:dw
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
yes tkhunny that was the original equation
 one year ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
Then I gave the correct 1st Derivative and you should use parentheses to clarify your meaning. Remember your Order of Operations.
 one year ago

tkhunny Group TitleBest ResponseYou've already chosen the best response.1
gtg sorry.
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
rapahael can you still help?
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
yes
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
so do I need to set the numerator =0
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
yes, because if the tangent line is horizontal, his angular coefficient is zero
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
so then I end up with cosx=1/2
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
yes
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
so is that my only x value , 1? ( my reasoning behind that is that cos of 60degrees=1/2) so then y x value is 1?
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
dw:1372217864898:dw
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
pipi/3,pi+pi/3
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
@trusev1 get it?
 one year ago

trusev1 Group TitleBest ResponseYou've already chosen the best response.0
I get that but it is asking for the xvalues that are at the line tangent is horizontal. so we got the derivative and even from your picture both those points would have the same xvalue.
 one year ago

RaphaelFilgueiras Group TitleBest ResponseYou've already chosen the best response.0
no. my figure isnt the graph of your question,it's just the trigonometric circle
 one year ago
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