Answer:
At approximately x = 0.08 and x = 3.92.
Step-by-step explanation:
The height of the ball is modeled by the function:

Where f(x) is the height after x seconds.
We want to determine the time(s) when the ball is 10 feet in the air.
Therefore, we will set the function equal to 10 and solve for x:

Subtracting 10 from both sides:

For simplicity, divide both sides by -1:

We will use the quadratic formula. In this case a = 16, b = -64, and c = 5. Therefore:

Substitute:

Evaluate:

Simplify the square root:

Therefore:

Simplify:

Approximate:

Therefore, the ball will reach a height of 10 feet at approximately x = 0.08 and x = 3.92.
Answer:
A = 40°
B = 50°
Step-by-step explanation:
If cos A = sin B, then A + B = 90
So, 2x/3 + 20 + 2x - 10 = 90
2x + 60 + 6x - 30 = 270
8x + 30 = 270
8x = 240
x = 30
2x/3 + 20 = 60/3 + 20 = 20 + 20 = 40
2x - 10 = 2(30) - 10 = 60 - 10 = 50 or 90 - 40 = 50
Answer:
Domain: (-infinity, +infinity) since you can pick any x values.
Range: [0, +infinity) since it does not go below the x axis.
Step-by-step explanation:
The graph is a parabola given by 
lets pick a few x values:
x = 1 gives us y = 1^2, which = 1
x = -1 gives us y = (-1)^2, which = 1
The parabola's domain is any x value as it extends to infinity.
For its range, you can see that it does not go below the x axis at x = 0. Therefore, the range of the parabola is from [0, infinity]
Answer:
see explanation
Step-by-step explanation:
Since p(x) = x² + 2 , if x ≤ 4
For x = 4 then this is included in the inequality x ≤ 4
whereas x > 4 does not include x = 4 but values greater than 4
Thus to evaluate x = 4 use p(x) = x² + 2
Answer:
The number of nickel coins is 10 and the number of quarter coins is 5
Step-by-step explanation:
<u><em>The correct question is</em></u>
Mary has 15 coins with the total value of $1.75 if the coins are nickels and quarters how many of each kind are there
Let
x ----> the number of nickel coins
y ----> the number of quarter coins
Remember that


we know that
Mary has 15 coins
so
-----> equation A
The total value of the coins is $1.75
so
----> equation B
Solve the system by graphing
Remember that the solution is the intersection point both graphs
using a graphing tool
The solution is the point (10,5)
therefore
The number of nickel coins is 10 and the number of quarter coins is 5