Can anyone help me with this problem? Many thanks! -bigclap [/URL][/IMG] Give the perimeter of the quadrilateral in simplest radical form Give area of quad ABCD ps, please show work, otherwise i won't understand it
What math level are you in? Because the easiest way is to do a double integral, but if you're not in the third part of Calculus, no point in me to do the work
Woah, how did I miss this? Okay, so first of all, for this problem, you'll need to find the values for each point A, B and C, no need to find D. Then use the equation to find the distance between the 2 points to find the lengths for AB and BC. Finally, just multiply them together and you'll get the area of ABCD. To find A(x,y) do as follows: x-3y=2 --> x=2+3y, sub to x+y=6, you have 2+3y+y=6 --> y=1 sub back to x-3y=2 & you'll find that x=5 So A(5,1) For B: x+y=6 --> x=6-y sub to -x+3y=-10 --> -6+y+3y=-10 --> y=-1 sub to x+y=6 --> x=7 So B(7,-1) For C: x+y=-2 --> x=-2-y sub to -x+3y=-10 --> 2+y+3y=-10 --> y=-3 sub back to x+y=-2 --> x=1 So C(1,-3) For the lengths of AB and BC, use this fomula: AB=square root of ((xb-xa)^2+(yb-ya)^2). You'll find that AB= 2 root 2, and BC= 2 root 10. Multiply them together & that'll give you the area of ABCD. Let me know if you are confused with anything. Good luck.
Good catch shy. Saw the equations and thought Calculus, didn't notice the parallel lines. However, the answer isn't correct. The slopes of the 2 different parallel lines are: y = 1/3x y = -x Because they are not negative reciprocals, they aren't perpendicular, so simply multiplying AB x BC won't work. :( We need to use a base x height method. We can use either AB or BC as the base, but we need a height, not just the other side, to figure out the area. So we can make an imaginary perpendicular line, then locate it's length and multiply it by the base to get our Area. (Edit: This is also like finding the distance between the parallel lines that you chose for the base). Or we can find one of the angles and use sin or cos (depending on which angle you found) and multiply it the unused solved bases already. Since it's extra credit Give it a shot, if you get stuck or don't understand what I'm talking about, we'll be here
Thanks a lot shy and avant! I understood your explanations very well. I can't believe all the work i put into finding the area and it turns out to be exactly 16... >< ( it IS 16, isn't it?)
Thanks for pointing that out. I totally missed that. But that was only because it was so late @ night. Well let's see... first you have to find the height. So, let's say y = 1x perpendicular to line AB and CD line AB: x + y = 6 replace y=1x --> x + 1x = 6 which gives you (3, 3) line CD: x + y + 2 = 0 replace y=1x --> x + 1x + 2 = 0 which gives you (-1, -1) Then you use the distance formula and plug in the 2 sets of points & that should leave you with the square root of 32 as the height. You then multiply that with the length of AB (2 root 2), which is the base. So, (root 32)*(2 root 2) = 2 root 64 = 2*8 = 16 So yeah, you got it!
Glad this thread hasn't already died down! It looks like I won't be needing any more hw help for now. Summer's here and school will be over in a week! Woohoo!! Many thanks to avant and shy for helping out so much.
-shock Is shy giving me an excuse? If you're going to give me one, atleast make up an original one. You get 1pt, and that's for effort only -whistle
calculus is not really that hard... its based on how welll u understand your highschool math =P calculating derivatives is a pain in the @** if you cant do arithmetic --___-- one mistake and you can blow your entire calculation. same for integrals... (except worse -lol)
Hey, I've got a couple questions that I cant do. Help please? 3. Binomial Distribution: You are allowed 25 spins of the shaved coin and you observe the following results: H H H T H H T H H H T T H T H H T H H H H T H T H Calculate the posterior probability of each hypothesis. Assume that you are indifferent as to whether the magician has shaved heads or tails on the coin and that the prior Betas for each hypothesis are modelled using parameter ratios of 20:10 or 10:20. >>> so I got 17heads and 8 tails. so I assume 20:10 means alpha 20, beta 10? how do I go about using these values? cheeers Also, does n.e. one know what a molar heat of solution is? And how would I calculate it? Help is needed urgently!!! thnx
Lychee: What are your hypotheses? That your parameters are a = 2b or vice versa? It seems that you need to do hypothesis testing, in which case, you're not giving enough info. When you have a binomial/beta combination X | theta ~ binomial (m, theta) theta ~ beta (a, b) then theta | X ~ beta (a*, b*) a* = a + nx(bar) b* = b + n(m - x(bar))
oh, i've figured it out already. thanks tho shy. Also this is not a hw question, but are you allowed to use calculators for the SATs?
With integrals, you can always check your work to see if you're right... like, take the derivative of the integrand to see if it comes out to be the same answer as what you were given. Calculus is not hard; you just have to be meticulous with your work. Like you said, one mistake, and you'll have to do the work all over again. It may be hard based on the textbook you're learning it from or the teacher who is teaching it, but if you understand the concepts, you should be able to solve every problem out there. There's always a definitive answer in math... it's not subjective, so it shouldn't be hard. You're allowed to use a calculator for both SAT II math tests - Math IC & IIC. It'd be more helpful to use a graphing calc for IIC. For IC, it doesn't matter if you have a calculator or not.
