Answer: sin
= ± 
Step-by-step explanation:
We very well know that,
cos2A=1−2sin²A
⟹ sinA = ±
As required, set A = & cos a= 
,thus we get
sin =± 
∴ sin =±
= ±
since ,360° < <450°
,180° < <225°
Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.
hope it helped!
Step-by-step explanation:
option C is correct....
Answer= 18
Explanation: you have to graph it on a grid paper first then make. Also trust me it’s the answer
Answer:
cos Θ = 
Step-by-step explanation:
Given the angle passes through (4, 5 ) then the right triangle with sides 4 and 5 has hypotenuse h given by
h² = 4² + 5² = 16 + 25 = 41 ( take the square root of both sides )
h = 
In relation to Θ, 4 is adjacent and 5 is opposite, thus
cos Θ = 
=
