Answer with Explanation:
Keep in mind these trigonometric Identity:
1. Cos²x - Sin² x= Cos 2 x
2. Cos 2 x = 2 Cos²x-1
3. Cos 2 x = 1 - 2 Sin²x
Now, Coming to the Problem
1 + Cos (18 x)
= 1 + Cos (2 × 9 x)
= 2 Cos ² (9 x)→→→ Cos (2 × 9 x)= 2 Cos² (9 x) - 1
You would plug in the values of each x.
Making, f(12) be 47, f(-4) be 7, and f(0) be 17
Answer:
-2 < a
Step-by-step explanation:
Let wind speed = x mph
when she rode 2 miles against the wind we have:-
speed = distance / time so
20 - x = 2 / t -------(1) where t is the time she took.
when riding with the wind we have
20 + x = 3 / t--------(2) adding equations (1) and (2):-
40 = 2/t + 3/t
40 = 5/t
t = 5/40 = 1/8 hr
x = 20 - 2 / 1/8 = 20 - 16 = 4
Wind speed was 4 mph Answer
X = 59/8 which equates to 7.375 or 7.
There’s only one possible value of x for that equation which is 7.
