Jan 10, 2016 · How do you evaluate [sin 70 degrees/cos(-430 degrees)] + tan(-70 degrees)?

Jul 29, 2016 · (sqrt2 + sqrt6)/4 Apply the trig identity: cos (a - b) = cos a.cos b + sin a.sin b cos (pi/3 - pi/4) = cos (pi/3).cos (pi/4) + sin (pi/3).sin (pi/4) = Trig table of ...

Apr 27, 2017 · To solve this, you need to know these formulae: #Sin (x+y) = Sin(x)Cos(y) + Cos(x)Sin(y)#-----equation 1 #Cos (x+y) = Cos(x)Cos(y) - Sin(x)Sin(y)#----equation 2

May 14, 2016 · int sin(x)cos(x) dx = 1/2 sin^2(x) + C Notice that using the power and chain rules we find: d/(dx) sin^2(x) = 2 sin(x) cos(x) So: int sin(x)cos(x) dx = 1/2 sin^2(x) + C

Jul 19, 2015 · Find sin (-pi/12) Answer: - 0.259 Call sin (-pi/12) = sin t -> cos 2t = cos (- pi/6) = cos (pi/6) = sqrt3/2 Use trig identity: cos 2t = sqrt3/2 = 1 - 2sin^2 t 2sin^2 t = (2 - sqrt3)/2 sin^2 t = (2 -sqrt3)/4 sin t = sin (-pi/12) = +- sqrt(2 - sqrt3)/2 = +- 0.259. Only the negative answer is accepted: …

Apr 7, 2016 · 0, pi, (2pi)/3, (4pi)/3, 2pi sin 2x + sin x = 0 Apply the identity: sin 2x = 2sin x.cos x 2sin x.cos x + sin x = 0. sin x(2cos x + 1) = 0 a. sin x = 0 --> x = 0, x = pi and x = 2pi b/ 2cos x + 1 = 0 cos x = -1/2 --> x = +- (2pi)/3 Answers for (0, 2pi): 0, pi, (2pi)/3, (4pi)/3, 2pi Reminder arc (4pi)/3 is co-terminal to arc -(2pi)/3

Nov 18, 2015 · Find sin 2x, knowing cos x = 5/13 Ans: -120/169 cos x = 5/13. Find sin x. sin^2 x = 1 - cos^2 x = 1 - 25/169 = 144/169 --> sin x = +- 12/13. Since x is in Quadrant IV, then sin x is negative. sin x = - 12/13. sin 2x = 2sin x.cos x = 2(-12/13)(5/13) = -120/169

Apr 6, 2018 · #Tan^2x-sin^2x # #=> sin^2x/cos^2x-sin^2x # #color(white)(wwwwwwwww# #["as " tanx = sinx/cosx]# #=> (sin^2x - sin^2xcos^2x)/cos^2x#

Feb 17, 2016 · How do you solve # cos (x/2) - sinx = 0# over the interval 0 to 2pi? Trigonometry Trigonometric Identities and Equations Solving Trigonometric Equations 1 Answer

Apr 11, 2016 · and # sin(pi/3) = (sqrt3)/2 , sin(pi/6) = 1/2 # substituting these values into the right side of the expansion. #= [1/2xx(sqrt3)/2] +[ (sqrt3)/2xx 1/2] = 1/4 sqrt3 + 1/4 sqrt3 = 1/2 sqrt3#