is cos theta 120 = -0.5?
956077
cos(180)=cos(180-120)= -sin60=  -o.5\nnegative sign because cos is - in ii quadrant.\nyou are absolutely right
807068
(-1.6875) (81) (0.28125) = 38.443359375\n\nIf thats not right, sue me.
757859
haha, k  Draw a picture and draw a free-body diagram.\n\nI don't feel like busting out a paper/pencil  so I'll try it in my mind\n\nF(sub g) cos Theta  =  Mg cos(20 degrees)\n\nbecause the Normal force is equal to the y-component of gravity.\n\nTwo similar triangles, the incline and one which has the Force of gravity straight down, and the y compentn equal opposite of the normal force, and X component equal opposite to F\n\n\nlots of physics i'm skipping in my explanation tho
369074
No.\n\nHere are the "sames'".\n\nSin(60 deg) = Cos(30 deg) = 0.866\nSin(30 deg) = Cos(60 deg) = 0.5\nSin(45 deg) = Cos(45 deg) = 0.7071\n\nIn general, Sin(x deg) = Cos([90 - x] deg)\nFor all real x.\n\nRegards
59453
Using your unit circle, you can see that:\nsin 30 = sin 150 = -sin 210 = -sin 330 and\ncos 10 = cos 350 = -cos 170 = -cos 190\n\nThis illustrates some basic identities which you should memorize, namely that\n\nsin (180 - x) = sin x and sin (-x)= - sin x\nand\ncos (180 - x) = -cos x and cos (-x) = cos x\n\nThese are probably in the front or back cover of your textbook.  :)
979494
37/120\n10/120=10/12\n55/120=11/24
601534
To convert from polar to cartesian co-ordinates, yousimply use:\n\nx = r cos (theta)\n\nand:\n\ny = r sin (theta)\n\nYou have radians - so make sure your calculator is set to radians.  This gives:\n\nx = 15 × cos (2.75) = -13.864...\ny = 15 × sin (2.75) = 5.7249...
1159579
cos55=sin(90-55)=sin35\ncos^2 55° + cos^2 35° =\nsin^2 35° + cos^2 35° =  1,\nbecause for any number of degrees;\nsin^2 + cos^2 = 1
269336
To solve this problem, you have to substitue the coordinates into point-slope form using the slope (-5) as m.  The y1 refers to the y coordinate, while the x1 refers to the x coordinate.\n \ny-y1=m(x-x1)\ny+12=-5(x+12)\ny+12=-5x-60\ny=-5x-72\n\nslope=-5\ny-int.=-72\n\nThe person above me has everything right except when she had -12=-5(-12)+b.\n-12=-5(-12)+b\n-12=60+b\n-72=b\nb=y-int=-72
45380
its simple ... 80*70*60 ... 10*0 = 0 !!\n\nright isnt it ??? :D
224437
You need to explain where points R,S,P,Q are.  All that is certain from your information is that LM is 120/13 and KM is 12.
664950
In the polar coordinate system r is always positive. It´s the distance from the origin to the point. \n\nThe transformation to rectangular (or rather carthesian) coordinates is as follows:\n\nx = r cos (theta)\ny = r sin (theta)\n\nSo assuming (r,theta) = (5,52 deg) I find\n\nx = 5 cos (52 deg) = 3.08\ny = 5 sin (52 deg) = 3.94 (both rounded off to two decimals)
701385
√605 = √(121*5) = 11√5
1099099
cos175\n= cos(180 - 5)\n= -cos5\n\nNow, cos15 \n= cos(45 - 30) \n= cos45*cos30 + sin45*sin30\n= {1/sqrt(2)}*{sqrt(3)/2} + {1/sqrt(2)}(1/2)\n\nThus cos15 can be calculated.\n\nNow, cos(3*5) = 4*(cos5)^3 - 3*cos5\nor cos15 = 4*(cos5)^3 - 3*cos5\n\nSolve this cubic in (cos5) to get its value.\n\nHence you get cos175.
998343
divide 120 by .5 you get 240 \ny=240 \n\nto check 240x.5=120
1067524
15 cis 270 divided by 3 cis 150 is\n5 cis 120   [(15/3) cis (270-150)]\n5 cis 120 in standard form will be  5(cos120 + i sin120)\n                                                      = -2.5 + 4.33 i
310302
using @ for angle theta:\n\nx = r cos @, y = r sin @, use cos^2 @ + sin^2 @ = 1\n\nr^2 = 1/4*(1-5/4*sin^@)