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UnbelievableDreams
 one year ago
Confusing math question
UnbelievableDreams
 one year ago
Confusing math question

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UnbelievableDreams
 one year ago
Best ResponseYou've already chosen the best response.0Find all values of theta in the interval [0, 360] that have the given function valve. cos theta = 1/2

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Do you know your special triangles, 304560

UnbelievableDreams
 one year ago
Best ResponseYou've already chosen the best response.0No, I think.

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2dw:1437017727352:dw

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2These are the special triangles, you should try to remember them, so we're given \[\cos \theta =  \frac{ 1 }{ 2 } = \frac{ adj }{ hyp }\] so what is it

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Once we figure out the triangle, we can use the following information to find the quadrants it is in.

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2So for now, jut figure out \[\cos \theta = \frac{ 1 }{ 2 }\]

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Now we can figure out, where in the unit circle it would be negative, if you remember this thing called "CAST" dw:1437018190660:dw this shows where the trig ratios are positive

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2So if you drew out triangles, you would notice for example in quadrant 4, y is negative but x is positive and also r (where x = adjacent, y = opposite, r = hypotenuse) and in quadrant 1 they are all positive, so quadrant 4 means costheta is positive, A means all positive, s means sin theta is positive, and t means tangent is positive.

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Sort of getting it?

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2dw:1437018375815:dw

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2So where in here would cos theta be negative?

UnbelievableDreams
 one year ago
Best ResponseYou've already chosen the best response.0@Astrophysics

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Well the quadrants here mean they are all positive in the certain area, so where it shows C that means it's positive, A means all of the ratios here are positive there, so for it to be negative it must be in Q2 and Q3 right?

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2So for quadrant 2 we have \[Q_2: 180  60 = ...\]and for quadrant 3 we have \[Q_3: 180 + 60 = ...\]

Astrophysics
 one year ago
Best ResponseYou've already chosen the best response.2Yup, those are your values then in the interval [0,360] :)
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