A (-7,1) B (7,1) C (-7,-1) D (7,-1)

Find the focus and directrix of y=4x^2

Mkey [24]

Hello there

the answer is

(0,1/16)

hope my answer helps

thank you !

5 0

3 years ago

Please help me with this.

Afina-wow [57]

Answer:

B

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Given a function <img src="https://tex.z-dn.net/?f=f%28x%29%3D3x%5E4-5x%5E2%2B2x-3" id="TexFormula1" title="f(x)=3x^4-5x^2+2x-3"

Levart [38]

Answer:

$\huge\boxed{f(-1) = -7}$

Step-by-step explanation:

In order to solve for this function, we need to substitute in our value of x inside to find f(x). Since we are trying to evalue f(-1), we will substitute -1 in as x to our equation.

$f(-1) = 3(-1)^4 - 5(-1)^2 + 2(-1) - 3$

Now we can solve for the function by multiplying/subtracting/adding our known values.

Starting with the first term to the last term:

$3(-1)^4 = 3$

WAIT! How is this possible? $-1^4 = -1$ (according to my calculator), and $3 \cdot -1 = -3$ , not 3!

It's important to note that taking a power of a negative number and multiplying a negative number are two different things. Let's use $-2^2$ as an example.

What your calculator did was follow BEMDAS since it wasn't explicitly told not to.

BEMDAS:

- Brackets

- Exponents

- Multiplication/Division

- Addition/Subtraction

Examining the equation, your calculator used this rule properly. Note that exponents come over multiplication.

So rather than being "-2 squared" - it's "the negative of of 2 squared."

Tying this back into our problem, the squared method would only be true if it looks like $-1^4$ . However, since we're substituting in -1, it looks like $(-1)^4$ , so the expression reads out as "-1 to the fourth."

MULTIPLYING -1 by itself 4 times results in $-1\cdot-1\cdot-1\cdot-1=1$ .

Applying this logic to our original term, $3(-1)^4$ :

$3(-1\cdot-1\cdot-1\cdot-1)$
$3(1)$
$3$

Therefore, our first term is 3.

Let's move on to our second and third terms.

Second term: $-5x^2$

$-5(-1)^2$

Applying the same logic from our first term:

$-5(-1 \cdot -1)$
$-5(1)$
$-5$

Third term: $2x$

$2(-1) = -2$

-3 is just -3, no influence of x.

Combining our terms, we have $3-5-2-3$ .

This comes out to be -7, hence, the value of $f(-1)$ for our function $f(x)=3x^4-5x^2+2x-3$ is -7.

Hope this helped!

4 0

3 years ago

Read 2 more answers

There were 8 red cars and 12 blue cars in the parking lot what is the ratio of the number of red cars to number of blue cars

salantis [7]

Answer:

2 : 3

Step-by-step explanation:

Hello fellow human!

red : blue - 8 : 12

The ratio is divisible by 4 - (8/4) = 2 ; (12/4) = 3

Hence, 2 : 3

8 0

2 years ago

Dave has $8000 to invest for 15 years. He finds a bank that offers an interest rate of 3.1% compounded monthly. How much money w

ioda

Dave will have $12,728 after 15 years, if he has $8000 to invest for 15 years. He finds a bank that offers an interest rate of 3.1% compounded monthly.

Step-by-step explanation:

The given is,

Investment = $ 8000

No. of years = 15 years

Interest rate, i = 3.1 %

( compounded monthly )

Step:1

For for calculating future value with compound interest monthly,

$A = P (1 +\frac{r}{n})^{nt}$ .................(1)

Where,

A = Future amount

P = Initial investment

r = Rate of interest

n = Number of compounding in a year

t = Time period

Step:2

From given values,

P = $8000

r = 3.1%

t = 15 years

n = 12 ( for monthly)

Equation (1) becomes,

$A = 8000( 1+\frac{0.031}{12} )^{(12)(15)}$

$= 8000 (1+0.002583)^{180}$

$= 8000(1.002583)^{180}$

$= 8000(1.591059)$

$=12728.48$

A = $ 12728.48

Result:

Dave will have $12,728 after 15 years, if he has $8000 to invest for 15 years. He finds a bank that offers an interest rate of 3.1% compounded monthly.

8 0

3 years ago