Modelling with polynomials and rational functions

In summary, the height of a diver above a swimming pool at time t seconds can be modeled by the function x(t)= 3- 3t (3t^2/2). To find the maximum height reached by the diver, we need to determine the value of t when the function reaches its maximum. This occurs when t=1, so the maximum height reached by the diver is 3 metres. After exactly 2 seconds, the diver hits the water. To find the depth of the water half a second after the diver hits the water, we can plug in t=2.5 into the function and get a value of 1.125 metres, or 112.5 cm.
  • #1
anzgurl
8
0
4 The height, x metres, of a diver above a swimming pool at time t seconds after he has bounced from the diving board can be modeled by the function x(t)= 3- 3t (3t^2/2)
a How long, in seconds, after he has bounced from the diving board does the diver
reach his maximum height?
b What is the maximum height reached by the diver, in metres?
c After exactly how many seconds does he hit the water?
d How deep is the diver half a second after he hits the water, assuming that the model
remains valid for this time?
Give your answer to the nearest centimetre.


i really need help with part d. i don't understand the question. could someone please help me?

thank you
 
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  • #2
If you know how long it takes for him to hit the water, just plug in t+1/2 to the polynomial.
 
  • #3
for your question. I will do my best to assist you with part d.

To answer part d, we first need to understand what the question is asking for. It is asking for the depth of the diver half a second after he hits the water. This means we need to find the height of the diver at t=0.5 seconds.

To find this, we can plug in t=0.5 into the given function x(t)=3-3t(3t^2/2). This gives us x(0.5)=3-3(0.5)(3(0.5)^2/2)= 3-1.125=1.875 meters.

Therefore, the depth of the diver half a second after he hits the water is 1.875 meters. This can also be written as 187.5 centimeters (since 1 meter = 100 centimeters).

I hope this helps you understand how to approach part d. If you have any further questions, please let me know. Good luck!
 

1. What is a polynomial function?

A polynomial function is a mathematical function that is made up of variables raised to non-negative whole numbers and multiplied by coefficients. It can have multiple terms and its degree is determined by the highest exponent in the equation.

2. How do you graph a polynomial function?

To graph a polynomial function, you can use either a graphing calculator or a table of values. First, substitute different values for the independent variable and solve for the dependent variable. Then, plot these points on a graph and connect them with a smooth curve. The end behavior of the graph will depend on the degree and leading coefficient of the polynomial.

3. What is a rational function?

A rational function is a mathematical function that is made up of a polynomial function in the numerator and denominator. It can also be written as a ratio of two polynomial functions. The denominator cannot equal zero, as this would result in an undefined value.

4. What is the domain of a rational function?

The domain of a rational function is all real numbers except for the values that make the denominator equal to zero. This is because these values would result in an undefined value, and therefore cannot be included in the domain.

5. How do you solve rational functions?

To solve rational functions, you must first simplify the function by factoring both the numerator and denominator. Then, set the numerator equal to zero and solve for the variable. These solutions are called the vertical asymptotes. Next, set the denominator equal to zero and solve for the variable. These solutions are called the horizontal asymptotes. Finally, plot these points on a graph and use them to determine the behavior of the graph.

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