<img src="https://tex.z-dn.net/?f=x%20%3D%20%20%5Cfrac%7Bb%20%2B%20%20-%20%20%5Csqrt%7B%7Bb%7D%5E%7B2%7D%20-%204ac%20%7D%20%7D%7

All categories

3 years ago

B2a%7D%20" id="TexFormula1" title="x = \frac{b + - \sqrt{{b}^{2} - 4ac } }{2a} " alt="x = \frac{b + - \sqrt{{b}^{2} - 4ac } }{2a} " align="absmiddle" class="latex-formula">
O True
O False

Mathematics

1 answer:

Phantasy [73]3 years ago

3 0

If it is asking if that equation is the quadratic formula, then the answer is false. The reason why is that the first 'b' should be negative

The quadratic formula is

$x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}$

You might be interested in

walnut grower estimates from past records that if 20 trees are planted per acre, then each tree will average 60 pounds of nuts p

laila [671]

Answer:

5 trees should be planted to maximize the yield per acre,

The maximum yield would be 1250

Step-by-step explanation:

Given,

The original number of trees per acre = 20,

Average pounds of nuts by a tree = 60,

Let x be the times of increment in number of trees,

So, the new number of trees planted per acre = 20 + x

∵ for each additional tree planted per acre, the average yield per tree drops 2 pounds,

So, the new number of pounds of nut = (60 - 2x)

Thus, the total yield per acre,

$Y(x) = (20+x)(60-2x)$

Differentiating with respect to t ( time ),

$Y'(x) = (20+x)(-2) + 60 - 2x = -40 - 2x + 60 - 2x = 20 - 4x$

Again differentiating with respect to t,

$Y''(x) = -4$

For maxima or minima,

$Y'(x) = 0$

⇒ 20 - 4x = 0

⇒ 20 = 4x

⇒ x = 5,

For x = 5, Y''(x) = negative,

Hence, Y(x) is maximum for x = 5,

And, maximum value of Y(x) = (20+5)(60 - 10) = 25(50) = 1250,

i.e. 5 trees should be planted to maximize the yield per acre,

and the maximum yield would be 1250 pounds

4 0

3 years ago

Find the total surface area of this cuboid,<br> 5 cm<br> 4 cm<br> 6 cm

Tatiana [17]

Answer:

148

Step-by-step explanation:

Sa=2(lw+lh+wh)

Sa=2(4*5+4*6+5*6)

148=2(4*5+4*6+5*6)

3 0

3 years ago

Read 2 more answers

Big Ideas Math 7.4 Practice A 8th grade

ziro4ka [17]

Answer:

What do you mean

Step-by-step explanation:

I don’t understand

3 0

3 years ago

Read 2 more answers

If an average walk to the gas station is 15 minutes. why has my dad been gone for 11 years?

IgorC [24]

Answer:

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers

A researcher surveyed 220 residents of a city about the number of hours they

olga55 [171]

Answer:

Margin of error of 0.0485 hours.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1 - 0.95}{2} = 0.025$

Now, we have to find z in the Ztable as such z has a pvalue of $1 - \alpha$ .

That is z with a pvalue of $1 - 0.025 = 0.975$ , so Z = 1.96.

Now, find the margin of error M as such

$M = z\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

In this question:

$\sigma = 0.35, n = 220$

The margin of error is of:

$M = z\frac{\sigma}{\sqrt{n}}$

$M = 1.96\frac{0.35}{\sqrt{200}}$

$M = 0.0485$

Margin of error of 0.0485 hours.

5 0

3 years ago