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.
Answer:
Step-by-step explanation:
Yes. The commutative property of addition (as well as the commutative property of multiplication) applies to all real numbers, and even to complex numbers. As an example (for integers):
5 + (-3) = (-3) + 5
Answer:
Why
Step-by-step explanation:
Did you report my answer ?
Did u notice u lost 40 points so then u tricked me into answering it for free ?
Answer:
68.8
Step-by-step explanation:
(a+b)h/2
12.9+8.6 *6.4/2
Answer:
V = 396 cm³
Step-by-step explanation:
the volume (V) of the prism is calculated as
V = Ah ( A is the area of the triangular face and h the height of prism )
A = 
bh ( b is base and h perpendicular height )
here b = 9, h = 8 , then
A = × 9 × 8 = 4.5 × 8 = 36 cm² , so
V = 36 × 11 = 396 cm³
