sin{pi/7} X sin{2pi/7} X sin{3pi/7} = ?
924113
sin(pi/7)*sin(2pi/7)*sin(3pi/7)\nsin (pi/7) = sin (0.45 radians) =.4350\nsin (2pi/7)=  sin(.88 radians) =.771\nsin(3pi/7)=sin(1.35 radians) = .976\nThus the abswer is .435*.771*.976=.327
908544
sin 2a / (1 + cos 2a)\n\n(2 sin a cos a) / (1 + (2 cos ^2 a - 1) )\n\n2 sin a cos a / (2 cos ^2 a)\n\nsin a / cos a\n\ntan a
553445
42/15  /  7/3=\n\n42/15 * 3/7=\n\n[42*3]/[7*15]=\n\n[6*7*3]/[7*3*5]=\n\n6/5
857524
sec(72.3pi)=1.701301618\n\nfirst change the mode of ur calculator to radians and then press the sequence of keys.\n\nand sec =cos-1 not sin-1\nso if u want sec , find cos first and then its inverse.\ncosec=sin-1\nsec=cos-1 \ncot=tan-1
255897
The gentleman above has the formulas correct  but to finish your question pi=3.14 so 2pi would be 6.28
215612
C = 2 pi r\nif d = 24.2, r = 12.1\n\ntherefore C = 2 x pi x 12.1\n            = 76.03\n\nFor all the guys think i shud get a keyboard whacked on my head i explained how it shud be worked out and didnt just giv d answer. \n\nInstead of saying rubbish i suggest u at least confirm that my answer is correct!!
1169872
(7/(3x)) / (x/3)\n(7/(3x)) * (3/x)\n21/(3x^2)\n7/x^2\n\nBut if you meant\n\n((7/3)x)/(x/3)\n((7x)/3)*(3/x)\n(21x)/(3x)\nANS : 7\n\n-------------------------------\n\n2 1/3 - 3/4\n2 1/3 = (7/3)\n\n(7/3) - (3/4)\nMultiply everything by 12\n(28 - 9)/12\n(19/12) or 1 (7/12)
913234
it's "pi" not "pie" dear ... :-)\n\nAnd, yes I do know how to prove those identities.\n\nAnd, no I won't do them all, as it will deprive you of the wonderful opportunity to learn and practice for your test. \n\nBut, I will do one for you!  I'll do #8:\n\n(sinx + cosx) ² =\nsin²x + 2sinxcosx + cos²x = \nsin²x + cos²x + 2sinxcosx = \n1 + 2sinxcosx  {{ using trig ID #1 }} = \n1 + sin2x {{ using trig ID #2 }}\n. . . . .\nTrig ID #1 :  sin²x + cos²x = 1\nTrig ID #2 :  sin2x = 2sinxcosx\n\nNRT
404800
sec = (1/cos); cot = (1/tan) = (cos/sin)\n\ncos(-pi/3) = 1/2 \n\n1/1/2 = 2 = sec(- pi/3)\n\ncos(-5pi/4) = -sqrt(2)/2 ;      sin(-5pi/4) = sqrt(2)/2\n\n(-sqrt(2)/2)/(sqrt(2)/2) = -1 = cot(- 5pi/4)\n\n2 - (-1) = 3 There's your answer.
884700
An entire circle has 2pi radians.  You just want pi/3 radians.  What part of 2 is 1/3?  In other words, what do you have to multiply pi/3 by to get 2pi.  (psst: it's 6).  So you want 1/6 of the circle's area.\n\npi/3 is an angle worth remembering.  The cosine of it is 1/2.
738055
π radians = 180°\nSo 2π radians = 360°\nSo 2π/3 radians = 360°/3\n= 120°
983394
Depends\n\nlim θ→π/2- (ie from below) tanθ = +∞\n\nlim θ→π/2+ (ie from above) tanθ = -∞ \n\nThis is because in the 1st quadrant tanθ >0 and in the second quadrant tanθ <0
385118
the circumference divided by 2 x PI
730722
put sinx=t\ncosxdx=dt\nI=fcos(pi t)dt with limits -1,+1\nI=(sin(pi t))/pi with limits +1,-1\nI=(sin(pi)-sin(-pi))/pi=0\nthanks & good luck
8473
7t+15 > 3t-13\n4t > -28\nt > -7
732786
Using Trig identity 2sin(x)cos(x) = sin2x\n\n(2sin3x)(cos3x) = sin6x
543335
sin^2(a) = 3/4 gives sin(a) = -sqrt(3)/2 or +sqrt(3)/2\n\nIf a it's in the third quadrant, sin(a) must be negative, so\nsin(a) = -sqrt(3)/2\n\nThis yields a = 210 degrees (7*pi/6 radians)\n\ntan(7pi/6) = sqrt(3)/3