Answer:
x = pi, 3pi, 5pi etc
x = -pi, -3pi, -5pi etc
Step-by-step explanation:
cos^2 x + 2 cos x + 1 = 0
replace cos x with m
m^2 + 2m +1 = 0
solve by factoring (this is a^2 +2ab+b^2 = (a+b)^2 where a =m and b=1)
(m+1)^2=0
take the square root of each side
m+1 =0
m=-1
now replace m with cos x
cos x = -1
take arccos of each side
arccos cos x = arccos (-1)
x = pi, 3pi, 5pi etc
To solve this problem, we are going to use the percent proportion, a/b = p/100, where a is the part of a number b, the whole, and p is the percentage out of 100.
When we fill in our known integers into this equation, we get
21.12 / b = 25.6 / 100
Next, to simplify this equation, we should use cross products (means - extremes products theorem). This means multiplying the numerator of one fraction and the denominator of the other fraction and setting them equal to one another.
21.12(100)=25.6(b)
When we multiply, you get
2112 = 25.6b
Finally, we divide both sides by 25.6, to get our variable b, alone, and without a coefficient.
82.5 = b
Therefore, 25.6% of the number 82.5 is 21.12.
If y varies directly with x, that means they change at proportion rates. We can define their relationship using a constant k.
y = kx
Plug in what we know to find k.
-3 = 5k
k = -3/5
So:
y = -1 * (-3/5)
y = 3/5
Step-by-step explanation:
4 tubes connected vertically.
each tube is 0.28 meters long.
it does not leave me any other form of interpretation than just to stack the tubes on top of each other.
4×0.28 = 1.12 meters
