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Lynna [10]
3 years ago
9

The function h ( t ) = − 3t 2 + 12 t + 63 models the flight of a ball t seconds after it is thrown. When can the ball be expecte

d to hit the ground
Mathematics
1 answer:
Oksana_A [137]3 years ago
4 0

As the ball hits the ground, its height will be equal to 0, so...

-3t² + 12t + 63 = 0

t² - 4t - 21 = 0

Using the Viet's theorem to solve the quadratic equation quicker:

t₁ + t₂ = 4

t₁t₂ = -21

t₁ = -3 - this is not possible because time can't be negative

t₂ = 7

That means, the ball is expected to hit the ground after 7 sec has passed.

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At the first meeting of the Tennis Club, the 7 members decided to have a tournament in which every player will play a match agai
mariarad [96]

Answer:

21 matches

Step-by-step explanation:

This is a combination problem where we have to select two member out of 7 members

 

So we want calculation of  7C2

 

   7C2 = 7!/[(2!)(7-2)!]

   (7*6*5*4*3*2*1)/[(2*1) *(5*4*3*2*1]

   (7*6)/2    ~  Note everything that easily cancels here!

   42/2

   21 matches

5 0
3 years ago
Can you factor -2x + 6 to get -2(x - 3)
QveST [7]

Answer:

Yes

Step-by-step explanation:

Divide -2x + 6 by -2, then bring the -2 outside the bracket

6 0
3 years ago
The volume (in cubic inches) of a shipping box is modeled by V =2x³ -19x² +39x, where x is the length (in inches). Determine the
yawa3891 [41]

Answer:

The values of x for which the model is 0 ≤ x ≤ 3

Step-by-step explanation:

The given function for the volume of the shipping box is given as follows;

V = 2·x³ - 19·x² + 39·x

The function will make sense when V ≥ 0, which is given as follows

When V = 0, x = 0

Which gives;

0 = 2·x³ - 19·x² + 39·x

0 = 2·x² - 19·x + 39

0 = x² - 9.5·x + 19.5

From an hint obtained by plotting the function, we have;

0 = (x - 3)·(x - 6.5)

We check for the local maximum as follows;

dV/dx = d(2·x³ - 19·x² + 39·x)/dx = 0

6·x² - 38·x + 39 = 0

x² - 19/3·x + 6.5 = 0

x = (19/3 ±√((19/3)² - 4 × 1 × 6.5))/2

∴ x = 1.288, or 5.045

At x = 1.288, we have;

V = 2·1.288³ - 19·1.288² + 39·1.288 ≈ 22.99

V ≈ 22.99 in.³

When x = 5.045, we have;

V = 2·5.045³ - 19·5.045² + 39·5.045≈ -30.023

Therefore;

V > 0 for 0 < x < 3 and V < 0 for 3 < x < 6.5

The values of x for which the model makes sense and V ≥ 0 is 0 ≤ x ≤ 3.

8 0
3 years ago
Select the equivalent expression.
Vanyuwa [196]

For this case we must find an expression equivalent to:(y ^ 3 * 2 ^ 5) ^ 2

By definition of power properties we have to meet:

(a ^ n) ^ m = a ^ {n * m}

So, rewriting the expression we have:

y^{3 * 2} * 2^ {5 * 2} =\\y^ 6 * 2^{10}

Answer:

Option B

y^6*2^{10}

4 0
4 years ago
What are my like terms here: <br><br> 4b, b, 7, 9b
netineya [11]

Answer:

4b, b, and 9b are like terms

Step-by-step explanation:

7 0
3 years ago
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