SOLUTION: Find the value of tan (a - b) if cos a= -3/5, sin b= 5/13, 90 < a < 180, and 90 < b

SOLUTION: Find the value of tan (a - b) if cos a= -3/5, sin b= 5/13, 90 < a < 180, and 90 < b < 180

Question 337106: Find the value of tan (a - b) if cos a= -3/5, sin b= 5/13, 90 < a < 180, and 90 < b < 180
Answer by CharlesG2(834) (Show Source): You can put this solution on YOUR website!
Find the value of tan (a - b) if cos a= -3/5, sin b= 5/13, 90 < a < 180, and 90 < b < 180

cos a = -3/5 = -0.6
a = 126.8699 degrees to 4 places

sin b = 5/13 = 0.3846 to 4 places

b = 22.6199 degrees to 4 places, but this is not between 90 and 180

sin 0 = 0, sin 45 = sqrt(2)/2 = 0.7071 to 4 places, sin 90 = 1,
sin 135 = sqrt(2)/2, sin 180 = 0

180 - b = 157.3801 degrees to 4 places, use this for b

tan (a - b) = tan (126.8699 - 157.3801) = tan (-30.5102)
tan (a - b) = -0.5893 to 4 places

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