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anonymous
 one year ago
Critical numbers help? I will reward with a medal!
anonymous
 one year ago
Critical numbers help? I will reward with a medal!

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\[\sin^2x+cosx\] \[0<x<2\pi\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Get that derivative? :U

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1\[\large\rm \sin x (2\cos x 1)=0\]Apply your ZeroFactor Property\[\large\rm \sin x=0\qquad\qquad\qquad 2\cos x1=0\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1sine is zero at what angles?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm not sure how to get that answer.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Don't remember your trig..? :(

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I was horrible at memorizing trig stuff. I enjoyed solving certain types of problems with them, but quite frankly I don't remember much of anything except for a few identities.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is it a particular formula, or is it just something you'd have to memorize?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Ugh OpenStudy freezing on me again.....

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0It does that to me a lot.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0(this may seem like a stupid question, but which part is sine?

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1dw:1444434276482:dwsine is the ycoordinates

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1So we want to know which angles give us a ycoordinate of 0

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Hmm there's another one :d

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oops! Didn't see that. The 0 angle

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Oh wait... was your interval really given like this? \(\large\rm 0<x<2\pi\) with strict inequality on BOTH sides?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That's what it looked like.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Oh ok :) Then I guess we can throw out the 0, since it's not in our interval. So then, \(\large\rm \sin x=0\) implies that our angle \(\large\rm x=\pi\). Ok great, we've found one critical point.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1\[\large\rm 2\cos x1=0\]Solving for cos x,\[\large\rm \cos x=\frac{1}{2}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1dw:1444434611166:dwCosine is your xcoordinates

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So 60 degrees for cosine?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I'm not sure why I keep looking only in the first section. Thank you again for pointing that out.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Degrees are icky :) lol You gotta try to get comfortable with radians XD

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Ok great so we've found all of our critical points!! \[\large\rm x=\frac{\pi}{3},~\pi,~\frac{5\pi}{3}\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Here is the graph in case you wanted to see it, it's pretty cool https://www.desmos.com/calculator/6sbfzaocym You can clearly see a hill top at pi/3 and 5pi/3 and the bottom of a valley at the pi.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Wow! I never knew you could graph something like this on desmos. That's very interesting.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0My connection on this site is horrible. sorry

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Thank you for your help! (I'll probably be back on here soon with more questions)

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1Yah it's a little complicated to graph just a small interval on desmos, you have to put it into set brackets { } and the interval comes first, then colon, then your function.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Could you help me with one last thing really quickly?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I know the derivative is sinx (2cosx 1) but I can't exactly figure out how to get that.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1oh you cheated on the first part? come on broski _

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0The assignment gives me the derivative

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1\[\large\rm y=(\sin x)^2+\cos x\]\[\large\rm y'=2(\sin x)(\sin x)'+(\cos x)'\]Start by applying power rule to the sine function. Then we have chain rule as well.

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1You really have to remember your sine and cosine derivatives to get through this one :)

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1\[\large\rm y'=2(\sin x)(\cos x)+(\sin x)\]

zepdrix
 one year ago
Best ResponseYou've already chosen the best response.1And then factor a sin x out of each term.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Oh okay! I see now. Thank you. :)
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