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3 years ago

For the function: f(x) = 21 + 2x − 5x2 Find f(3)

1 answer:

6 0

F(3)=-18

You just replace x for three for your equation and then use Ofer of operations to solve it.

So f(3)= 21+ 2(3)-5(3)^2

The exponent goes first: f(3)= 21+ 2(3)-5(9)

Next is multiplication: f(3)= 21+ 6-45

Now add: f(3)= 27-45

Finally subtract: f(3)= -18

Hope this helps!

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peggy is five years older than peter and susan is two years younger than peter the sum of their ages is 15 years how old is each

spin [16.1K]

Peggy is 9, Peter is 4, and Susan is 2
9+4+2=15

5 0

3 years ago

The body temperatures of adults have a mean of 98.6°F and a standard deviation of 0.60° F. Describe the center and variability o

amid [387]

Answer:

center = 98.6, variability = 0.08

Step-by-step explanation:

The Central Limit Theorem estabilishes that, for a random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sample means with size n of at least 30 can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$

The center is the mean.

So $\mu = 98.6$

The standard deviation of the sample of 50 adults is the variability, so

$s = \frac{0.6}{\sqrt{50}} = 0.08$

So the correct answer is:

center = 98.6, variability = 0.08

7 0

3 years ago

The area of a square quilt is 289 square inches. There is a smaller square patch on the quilt with an area of 121 square inches.

alisha [4.7K]

Area of a square quilt = 289 square inches
Area of a smaller square quilt = 121 square inches

Area of a square = a²

Side length of big square quilt = √289 in² = 17 inches
side length of small square quilt = √121 in² = 11 inches

Perimeter of big square = 17 inches * 4 = 68 inches
perimeter of small square = 11 inches * 4 = 44 inches

difference = 68 inches - 44 inches = 24 inches.

3 0

3 years ago

Read 2 more answers

Find two unit vectors orthogonal to both given vectors. i j k, 4i k

Maurinko [17]

The cross product of two vectors gives a third vector $\mathbf v$ that is orthogonal to the first two.

$\mathbf v=(\vec i+\vec j+\vec k)\times(4\,\vec i+\vec k)=\begin{vmatrix}\vec i&\vec j&\vec k\\1&1&1\\4&0&1\end{vmatrix}=\vec i+3\,\vec j-4\,\vec k$

Normalize this vector by dividing it by its norm:

$\dfrac{\mathbf v}{\|\mathbf v\|}=\dfrac{\vec i+3\,\vec j-4\,\vec k}{\sqrt{1^2+3^2+(-4)^2}}=\dfrac1{\sqrt{26}}(\vec i+3\,\vec j-4\vec k)$

To get another vector orthogonal to the first two, you can just change the sign and use $-\mathbf v$ .

6 0

3 years ago

The approximation of which irrational number is shown by point R on the number line?

Alenkasestr [34]

Answer:

B it is very simple my friend

Step-by-step explanation:

3.75 × 3.75 = 14.0

6 0

2 years ago