In Exercises 17 you are asked to find the sine cosine and ta
In Exercises 1-7 you are asked to find the sine, cosine and tangent of the double angle 2, as well as the quadrant 2 sits in, based on the given information on . Use exact values. Show work
1. cos = 8/17 , in QuadrantIV.
2. sin =7/25 , in QuadrantIII.
Solution
1. cos = 8/17 , in QuadrantIV.
sin = sqrt(1 -(8/17)^2) = -15/17 ( sin is -ve in IVrt quad)
sin2 = 2sincos = 2(8/17)(-15/17) = - 240/289
cos2 = 2cos^2 -1 = 2(8/17)^2 -1 = -161/289
tan2 = sin2/cos2 = 240/161
2. sin =7/25 , in QuadrantIII
cos = sqrt( 1 -sin^2) = sqrt( 1 -(7/25)^2) = - 24/25 (cos is -ve in QIII)
sin2 = 2sincos = 2*(-7/25)(-24/25) = 336/625
cos2 = 2cos^2 -1 = 2(-24/25)^2 -1 = 527/625
tan2 = sin2/cos2 = 336/527

