Answer:
a
Step-by-step explanation:
bc I just took the quiz☝
Answer:
-k-14
Step-by-step explanation:
Use distributive property and then just carry on and combine like terms.
Answer:
C
Step-by-step explanation:
Using sum/difference to product identity
• sin x - sin y = 2 cos() sin ()
with x = 4Θ and y = 2Θ
Then
sin(4Θ) - sin(2Θ)
= 2 cos() sin()
= 2cos(3Θ)sinΘ → C
<span>tan(15) =
sin(15) / cos(15) =
sin(45 - 30) / cos(45 - 30) =
[ sin(45)cos(30) - sin(30)cos(45) ] / [ cos(45)cos(30) + sin(45)sin(30)]
Since sin(45) = cos(45) = √2/2, you can just factor that out from the top and bottom
[ cos(30) - sin(30) ] / [ cos(30) + sin(30)]
[ √3/2 - 1/2 ] / [ √3/2 + 1/2]
(√3 - 1) / (√3 + 1)
(√3 - 1)^2 / (√3+1)(√3 - 1)
(√3 - 1)^2 / (3 - 1)
(3 - 2√3 +1) / 2
2 - √3
There's also a formula for tan(a-b), but I couldn't remember it off hand.</span>