Answer:
A & C
Step-by-step explanation:
To find the two expressions that are equivalent to 6.5 ÷ 1.3, you need to solve all of them until you get the two expressions that have a quotient of 5.
Let's begin solving!
65 ÷ 13 = 5
So now we know that A is one of our answers
65 ÷ 130 = 0.5
Not one of our answers because the quotient is not 5
650 ÷ 130 = 5
This is our other answer! We don't need to solve D because we only needed to find two expressions which are A and C.
Hope this helps you :)
168/3=56. 56 miles per hour.
Step-by-step explanation:
Elijah runs at constant speed
2.4 hours -----------> 13.8 miles
1 hour ---------------> 13.8/2.4
1 hour ---------------> 5.75 miles
Elijah run 5.75 miles in each hour at constant speed
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.
