Ask question

Ask question

All categories

3 years ago

14

I need help with this please help????

1 answer:

xenn [34]3 years ago

8 0

Answer:

D.29

Step-by-step explanation:

all you have to do is replace the x's with -2

4(-2)^2-3(-2)+7=4*4+6+7=16+6+7=22+7=29

You might be interested in

Find the point (,) on the curve =8 that is closest to the point (3,0). [To do this, first find the distance function between (,)

ELEN [110]

Question:

Find the point (,) on the curve $y = \sqrt x$ that is closest to the point (3,0).

[To do this, first find the distance function between (,) and (3,0) and minimize it.]

Answer:

$(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})$

Step-by-step explanation:

$y = \sqrt x$ can be represented as: $(x,y)$

Substitute $\sqrt x$ for $y$

$(x,y) = (x,\sqrt x)$

So, next:

Calculate the distance between $(x,\sqrt x)$ and $(3,0)$

Distance is calculated as:

$d = \sqrt{(x_1-x_2)^2 + (y_1 - y_2)^2}$

So:

$d = \sqrt{(x-3)^2 + (\sqrt x - 0)^2}$

$d = \sqrt{(x-3)^2 + (\sqrt x)^2}$

Evaluate all exponents

$d = \sqrt{x^2 - 6x +9 + x}$

Rewrite as:

$d = \sqrt{x^2 + x- 6x +9 }$

$d = \sqrt{x^2 - 5x +9 }$

Differentiate using chain rule:

Let

$u = x^2 - 5x +9$

$\frac{du}{dx} = 2x - 5$

So:

$d = \sqrt u$

$d = u^\frac{1}{2}$

$\frac{dd}{du} = \frac{1}{2}u^{-\frac{1}{2}}$

Chain Rule:

$d' = \frac{du}{dx} * \frac{dd}{du}$

$d' = (2x-5) * \frac{1}{2}u^{-\frac{1}{2}}$

$d' = (2x - 5) * \frac{1}{2u^{\frac{1}{2}}}$

$d' = \frac{2x - 5}{2\sqrt u}$

Substitute: $u = x^2 - 5x +9$

$d' = \frac{2x - 5}{2\sqrt{x^2 - 5x + 9}}$

Next, is to minimize (by equating d' to 0)

$\frac{2x - 5}{2\sqrt{x^2 - 5x + 9}} = 0$

Cross Multiply

$2x - 5 = 0$

Solve for x

$2x =5$

$x = \frac{5}{2}$

Substitute $x = \frac{5}{2}$ in $y = \sqrt x$

$y = \sqrt{\frac{5}{2}}$

Split

$y = \frac{\sqrt 5}{\sqrt 2}$

Rationalize

$y = \frac{\sqrt 5}{\sqrt 2} * \frac{\sqrt 2}{\sqrt 2}$

$y = \frac{\sqrt {10}}{\sqrt 4}$

$y = \frac{\sqrt {10}}{2}$

Hence:

$(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})$

3 0

3 years ago

Happy Paws charges $19.00 plus $3.50 per hour to keep a dog during the day. Woof Watchers charges $11.00 plus $4.75 per hour. Co

Nataly_w [17]

19.00 3.50 11.00 4.47 makes it add up to hours so that will be answe C

3 0

2 years ago

Find the distance between (3,4) and (4,-6) if necessary, round to the nearest tenth.

Ratling [72]

Answer:

The distance is:

d = 10.0 units (Rounded to the nearest the Tenths Place)

Step-by-step explanation:

Given the points

(3,4)

(4,-6)

The distance 'd' between (3,4) and (4,-6)

$\mathrm{Compute\:the\:distance\:between\:}\left(x_1,\:y_1\right),\:\left(x_2,\:y_2\right):$

$d=\sqrt{\left(x_2-x_1\right)^2+\left(y_2-y_1\right)^2}$

substituting the points values

$=\sqrt{\left(4-3\right)^2+\left(-6-4\right)^2}$

$=\sqrt{1+10^2}$

$=\sqrt{1+100}$

$=\sqrt{101}$

$=10.0$ units (Rounded to the nearest the Tenths Place)

Thus, the distance is:

d = 10.0 units (Rounded to the nearest the Tenths Place)

4 0

3 years ago

How do find the answer in subtractiion problem, when the top number is smaller than the bottom

Travka [436]

Use a number line if you need 4/10 - 6/10 = -2/10a simpler way is to do the opposite 6/10 - 4/10 = 2/10 then the answer would be the opposite as well. so, -2/10

8 0

3 years ago

Read 2 more answers

How do you write 8 million, 6 ten-thousan, 3 hundred ,9ones?

erica [24]

8,610,309 should be it

3 0

3 years ago