Ask question

Ask question

All categories

3 years ago

9

Graph the function f(x) = x3 – 4x – 1. Which are approximate solutions for x when f(x) = 0?

2 answers:

MAVERICK [17]3 years ago

6 0

Answer:

x = 1, √5, -√5

Step-by-step explanation:

Graphing of Function:

The given function will cut the y-axis at (0,-1) and it will cut the x-axis at (0,1),(0,√5), (0.-√5).

We are given the function f(x) = $x^3 - 4x - 1 = 0$

We have to approximate the solutions when f(x) = 0, that is,

f(x) = $x^3 - 4x - 1 = 0$ = 0

⇒ $x^3 - 4x = 1$

⇒ $x(x^2 - 4) = 1$

⇒ x = 1, $x^2 - 4 = 1$

Now, $x^2 - 4 = 1$

⇒ $x^2 = 5$

⇒ x = ±√5

Thus, x = 1, √5, -√5

Scilla [17]3 years ago

5 0

If f(x) is = to 0 then that means that you would have to plug the 0 in for all of the x that are in the function and the solve it.
f(x)= x3-4x-1
f(0)= (0)3-4(0)-1
0 0 0 -1
-1
so that means that -1 would be the answer for the function

You might be interested in

to fill a coffee mug at a local shop costs $2.50. the shop sells coffee beans foe $12 per pound. each pound makes enough coffee

myrzilka [38]

Answer:

There are a few possible answers so read explanation, but the one I will put up here is:

20.83

Step-by-step explanation:

First you have to find how much 100 cups of coffee costs in store.

To do this you will multiply 2.50 by 100 and get 250. So now we know 100 cups of coffee in store costs $250 whereas 100 cups at home is $12.

To find how many times greater the price in store is compared to the at home brew, you have to divide 250 by 12 and get 20.8333333....

We don't stop there though, because it asks us to approximate. I am not sure what it would like us to round to, but here are some possible approximations:

20.83
20.8
21

Any of those re reasonable approximations, you choose whichever you think the question wants, or whatever your teacher asks for.

Hope this helps

3 0

3 years ago

Cross product property

Klio2033 [76]

Using the cross product property on this proportion gives us the following equation:

20 (2x - 9) = 10 (9)

Use the distributive property and multiply

40x - 180 = 90

Add 180 to both sides

40x = 270

Divide 40 from both sides

x = 270/40

Simplify fraction

x = 27/4

This should be your answer. Let me know if you need any clarifications, thanks!

8 0

3 years ago

Which of the following is the explicit rule for a geometric sequence defined by a recursive formula of for which the first term

Allushta [10]

.it should be C for the question

4 0

3 years ago

Read 2 more answers

3. Solve the system using elimination (not substitution or matrices). negative 2 x plus y minus 2 z equals negative 8A N D7 x pl

riadik2000 [5.3K]

Elimination Method

$\begin{gathered} -2X+Y-2Z=-8 \\ 7X+Y+Z=-1 \\ 5X+2Y-Z=-9 \end{gathered}$

If we multiply the equation 3 by (-1) we obtain this:

$\begin{gathered} -2X+Y-2Z=-8 \\ 7X+Y+Z=-1 \\ -5X-2Y+Z=9 \end{gathered}$

If we add them we obtain 0, therefore there are infinite solutions. So, let's write it in terms of Z

1. Using the 3rd equation we can obtain X(Y,Z)

$\begin{gathered} 5X=-9-2Y+Z \\ X=\frac{-9-2Y+Z}{5} \\ \end{gathered}$

2. We can replace this value of X in the 1st and 2nd equations

$\begin{gathered} -2\cdot(\frac{-9-2Y+Z}{5})+Y-2Z=-8 \\ 7\cdot(\frac{-9-2Y+Z}{5})+Y+Z=-1 \end{gathered}$

3. If we simplify:

$\begin{gathered} \frac{-9Y+12Z-63}{5}=-1 \\ \frac{9Y-12Z+18}{5}=-8 \end{gathered}$

4. We can obtain Y from this two equations:

$\begin{gathered} Y=-\frac{-12Z+58}{9} \\ \end{gathered}$

5. Now, we need to obtain X(Z). We can replace Y in X(Y,Z)

$\begin{gathered} X=\frac{-9-2Y+Z}{5} \\ X=\frac{-9-2(-\frac{-12Z+58}{9})+Z}{5} \end{gathered}$

6. If we simplify, we obtain:

$X=\frac{-3Z+7}{9}$

7. In conclusion, we obtain that

(X,Y,Z) =

$(\frac{-3Z+7}{9},-\frac{-12Z+58}{9},Z)$

8 0

1 year ago

Paula puts an initial $600 into a savings account. The account has a 7% annual compound interest rate. Find the amount of money

Alexxandr [17]

$600*0.07*9 years= $10

3 0

2 years ago