<h3>
Answer: 42</h3>
Explanation:
We have y = -0.9x^2 + 76x - 250 which is in the form y = ax^2+bx+c
where,
The vertex (h,k) is when the profit is maxed out.
h = -b/(2a)
h = -76/(2(-0.9))
h = 42.222 approximately
Let's plug in x values around x = 42
Try x = 41
y = -0.9x^2 + 76x - 250
y = -0.9(41)^2 + 76(41) - 250
y = 1353.10
Now try x = 42
y = -0.9x^2 + 76x - 250
y = -0.9(42)^2 + 76(42) - 250
y = 1354.4
Now try x = 43
y = -0.9x^2 + 76x - 250
y = -0.9(43)^2 + 76(43) - 250
y = 1353.9
We see that the largest profit happens when x = 42.
The answer is the letter B
Answer:
see below
Step-by-step explanation:
<h3>Given</h3>
- Distance is 142.2 m, correct to 1 decimal place
- Time is 7 seconds, correct to nearest second
<h3>To find:</h3>
- Upper bound for the speed
<h3>Solution </h3>
<em>Upper bound for the speed = upper bound for distance/lower bound for time</em>
- Upper bound for distance = 142.25 m (added 0.1/5 = 0.05)
- Lower bound for time = 6.5 seconds (subtracted 1/2 = 0.5)
<u>Then, the speed is:</u>
- 142.25/6.5 = 21.88 m/s
- 21.88 = 21.9 m/s correct to 1 decimal place
- 21.88 = 22 m/s correct to nearest m/s
Answer:
h = 24 cm
Step-by-step explanation:
The formula for area of a triangle is
A = (1/2)bh where b is the base and h is the height.
We are told that the base is 5 times the height, this translates to
b = 5h, so we can rewrite our formula to
A = (1/2)(5h)(h) or
A = (1/2)5h²
We are given A = 1,440, so plug that in and solve for h...
1,440 = (1/2)5h²
2,880 = 5h² (multiply both sides by 2 to get rid of the fraction)
576 = h² (divide both sides by 5 to get the h value by itself)
24 = h (take the square root of both sides)
I can use the angle and the length of JH to find the length of IJ.
To do this, I look at the relationship IJ and JH have to the 52 degree angle. JH is opposite to angle I, and IJ is adjacent to angle I. Because the two side lengths are opposite and adjacent, I use the tangent function to solve this.
Tangent of an angle = the length of the opposite side / the length of the adjacent side. This is just another way to say tan(x)=opposite/adjacent
Now I can fill in what I know...
tan(52)=4.2/x
Now, I want to isolate x.
tan(52) = 4.2/x
x(tan(52))=4.2
x=4.2/tan(52)
Now I put 4.2/tan(52) into a calculator and get x = 3.3 ft
Hope this helps!