Line that never touch each other
Answer:
D
Step-by-step explanation:
Using the Cosine rule to find AC
AC² = BC² + AB² - (2 × BC × AB × cosB )
= 18² + 12² - ( 2 × 18 × 12 × cos75° )
= 324 + 144 - 432cos75°
= 468 - 111.8
= 356.2 ( take the square root of both sides )
AC =
≈ 18.9
-----------------------------------------
Using the Sine rule to find ∠ A
=
( cross- multiply )
18.9 sinA = 18 sin75° ( divide both sides by 18.9 )
sinA =
, then
∠ A =
(
) ≈ 66.9°
17. Its answer C i wil tell you the other one in a sec
Answer:
Step-by-step explanation:
discriminant = (-13)² - 4·2·15 = 49
discriminant > 0 so there are two real roots