<p>2sin(x) - sin(2x) = 4/pi</p>
<p>or rewritten as</p>
<p>2sin(x) - 2sin(x)cos(x) = 4/pi</p>
<p>or rewritten as</p>
<p>2sin(x)[1 - cos(x)] = 4/pi</p>
<p>thanks!</p>
<p>I'm at a loss. The answer is x = 1.238 or 2.808 +/- 2pi. I don't know of any irrational numbers like that from memory.</p>
<p>How did you solve it?</p>
<p>I graphed 2sin(x) - sin(2x) and 4/pi separately and used the intersection finder on my calculator.</p>
<p>Thats a SAT math??
do you mean ACT? because i have never seen any trig on the SAT</p>
<p>Its DEFINITELY on both the SAT and ACT</p>
<p>thanks arnoc, but I was thinking of doing it w/out the calculator(even though you can use it, obviously:))</p>
<p>My strategy was to figure out the number and then work backwards or try to figure out what the "exact" answer would be in terms of a radical or something. The only problem is that I have no idea what solution would come close to yielding those numbers, so I'm doubting that it could be solved without a calculator.</p>
<p>I used the solve( operator on my amazing TI-89 Titanium and yielded the same results as arnoc (though there are more answers due to the nature of pi).</p>
<p>a personal strategy i find VERY helpful, developed naturally is that whenever i find questions that require to solve for X, and it has only the same variable(meaning, can be XX-5X), i move everything to the left, use the solver function of TI 83, find the X to make the equation zero.
idk if theres 2 answers,but in less than 10 seconds,i got x=2.80812....</p>
<p>No,this kind of question will NOT show up on the SAT.
alipes, its not gona be there. maybe in SAT 2...not SAT 1</p>
<p>I hate the solver. I graph everything.</p>
<p>Ren, in answer to your idk, there's actually an infinite amount of answers. You know... 2pi, the unit circle? Good times.</p>
<p>Still a not-fun question =/.</p>
<p>This isn't SAT math...lol</p>
<p>thank you...thats what i was sayin!!</p>
<p>I thought you weren't supposed to post homework help questions here? (Or I would have a long time ago)</p>
<p>^ ouch...he just tricked us all making us think it was an SAT question..</p>
<p>..while it was his homework?</p>
<p>my point is, the one i stated is a very helpful strategy, to me at least. i know when to use it, it just comes naturally lol.. graphing sucks, u hav to wait for the graph to show,type in equation, and press numerous buttons, time-consuming. no good</p>
<p>anyway my point is u can apply that to any of the 'solve for x' questions.
reading the question correctly, knowing what the problem wants, it works with 100% accuracy for me.
let me give u an example of simple SAT math problems, that require u to use those gay ways to solve.</p>
<p>i remember the ester problem, that 2 way equal distance,diff rates and time.
lets say x/30+x/45=1
i believe that was the right numbers. dist/spd + dist/spd=1 hr
OK, when i see this type of problem, i go straight to my TI, i move everything to the right
x/30+x/45=1 -> 0=1-x/45-x/30, then u solve for x; like i said, this type of problem only takes about 10 seconds to find the right answer, idk if its gona work for u guys. but i developed it personally, so im very adept at it=p
same thing works for other things do some cross multiplying(many variables,but same variable.)
move everything to 1 side, equal 0, solve.</p>
<p>DEFINITE SAT material</p>
<p>SAT math only covers through algebra II for the most part. There aren't any trig questions on the SAT</p>
<p>unless what Alipes07 is implying is that the trig is SAT 2 material. No its not Sat reasoning test, its in SAT math 2 i believe.
i've seen thousands of math questions, i've never seen trig in SAT 1.
so dont argue. case closed.</p>