Answer:
9-8
Step-by-step explanation:
60 divided by 7 is 8.5
Answer:
147°
Step-by-step explanation:
The measure of arc CH is equal to the central angle it sees
the angles arc AH sees are BAC and CAH so the length of arc AH would be the sum of these two angles
90° + 57° = 147°
Answer: ? = -22.5
Step-by-step explanation:
Using a negative number to replace the ? turns the minus into a plus sign.
-21 - (-22.5) = 1.5 is the same as -21 + 22.5 = 1.5
Answer:
f(x) = 8x⁴-8x²+1
Step-by-step explanation:
I will assume that f(cos θ) = cos(4θ). Otherwise, f would not be a polynomial. lets divide cos(4θ) in an expression depending on cos(θ). We use this properties
- cos(2a) = cos²(a) - sin²(b)
- sin(2a) = 2sin(a)cos(a)
- sin²(a) = 1-cos²(a)
cos(4θ) = cos(2 * (2θ) ) = cos²(2θ) - sin²(2θ) = [ cos²(θ)-sin²(θ) ]² - [2cos(θ)sin(θ)]² = [cos²(θ) - ( 1 - cos²(θ) ) ]² - 4cos²(θ)sin²(θ) = [2cos²(θ)-1]² - 4cos²(θ) (1 - cos²(θ) ) = 4 cos⁴(θ) - 4 cos²(θ) + 1 - 4 cos²(θ) + 4 cos⁴(θ) = 8cos⁴(θ) - 8 cos²(θ) + 1
Thus f(cos(θ)) = 8 cos⁴(θ) - 8 cos²(θ) + 1, and, as a result
f(x) = 8x⁴-8x²+1.
