Answer:
84 degrees
Step-by-step explanation:
Applying the Cosine Rule (Choice 2 is the correct one) :-
12^2 = 11^2 + 6^2 - 2*11*6 cos Y
144 = 121 + 36 - 132 cos Y
cos Y = (121 + 36 - 144) / 132
cos Y = 0.09848
Y = 84.3 degrees
Answer:
-¹²/₅
Step-by-step explanation:
Let cos a = -⁵/₁₃
Then tan a = sin a/cos a
= [√(1 - cos²a)]/cos a
= {√[1 - (-⁵/₁₃)²]}/(-⁵/₁₃)
= -[√(1 - ²⁵/₁₆₉)] × ¹³/₅
= -[(√(¹⁴⁴/₁₆₉ )] × ¹³/₅
= -¹²/₁₃ × ¹³/₅
= -¹²/₅
tan(arccos (-⁵/₁₃)) = -¹²/₅
The diagram shows the 2nd quadrant of a circle with radius 13, cos a = -⁵/₁₃, and tan a = ¹²/₍₋₅₎ = -¹²/₅.