The answer is D. The first thing to do is to check units. The unit for the answer should be AUD since we are converting USD to AUD, so only C and D work. 1 USD is equal to 1.0343 AUD, instead of the other way around (1USD=0.9668AUD), which means 80 USD should be multiplied by 1.0343 AUD/1USD, because AUD is cheaper and there should be more AUDthan USD after conversion.
Y is going to be equal to four
Answer:
D and yes
Step-by-step explanation:
+ 1 = -3 If we multiply both sides of the equation by 4 will will get the second equation
(4) + (4) 1 = (4) -3
x + 4 = -12 We solve this for x by subtracting 4 from both sides.
x = -16
Plug -7 into both equations and you will see that it is a solution
+ 1 = -3
+ 1 = -3
-4 + 1 = -3
-3 = -3
x + 4 = =12
-16 + 4 = -12
-12 - -12
I hope this helps you
2×(7×7x^3-7×3)
2×[7 (7x^3-3)]
2×7×(7x^3-3)
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.