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2 years ago

10

decide which part of the quadratic formula tells you whether the quadratic equation can be solved by factoring. −b b2 − 4ac 2a u

se the part of the quadratic formula that you chose above and find its value, given the following quadratic equation: 2x2 7x 3 = 0

2 answers:

Romashka [77]2 years ago

4 0

Answer:

Step-by-step explanation:

A quadratic equation can be factorised if and only if there are rational roots.

For any quadratic equation the discriminant decides about the nature of roots.

Thus only if the discriminant is a perfect square we can have rational roots and in this case only factorization is possible.

In the given equation

$2x^2+ 7x+ 3 = 0\\a=2, b=7, c=3\\b^2-4ac = 1$

Since 1 is a perfect square we can factor and solve

$2x^2 +7x +3 = 0\\(2x+1)(x+3)=0\\x=-1/2 or x = -3$

Neko [114]2 years ago

3 0

If b^2 - 4ac is a perfect square, then the equation can be solved by factoring.

2x^2 + 7x + 3 = 0

a = 2, b = 7, c = 3

b^2 - 4ac = 7^2 - (4 x 2 x 3) = 49 - 24 = 25

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The following data is from a simple random sample of 12 students GPAs. 3.12 2.45 4.0 3.76 3.54 2.78 3.39 3.21 1.98 3.43 3.98 2.7

Rufina [12.5K]

Answer: 3. 2

Step-by-step explanation:

Given the data:

3.12 2.45 4.0 3.76 3.54 2.78 3.39 3.21 1.98 3.43 3.98 2.77

Point estimate of population mean :

Σx / N

(3.12 + 2.45 + 4.0 + 3.76+ 3.54 + 2.78 + 3.39 + 3.21 + 1.98 + 3.43 + 3.98 + 2.77)

= 38.41 / 12

= 3.2008

4 0

2 years ago

What is the product and reciprocal of 1/9

sukhopar [10]

Answer:

9

Step-by-step explanation:

The reciprocal of 1/9 is 9/1 which is just 9.

4 0

2 years ago

Read 2 more answers

Directions: Find the indicated trigonometric ratio as a fraction in simplest form. 1. Sin L =

Rainbow [258]

Answer:

$\sin L = 0.60$

$tan\ N = 1.33$

$\cos L = 0.80$

$\sin N = 0.80$

Step-by-step explanation:

Given

See attachment

From the attachment, we have:

$MN = 6$

$LN = 10$

First, we need to calculate length LM,

Using Pythagoras theorem:

$LN^2 = MN^2 + LM^2$

$10^2 = 6^2 + LM^2$

$100 = 36 + LM^2$

Collect Like Terms

$LM^2 = 100 - 36$

$LM^2 = 64$

$LM = 8$

Solving (a): $\sin L$

$\sin L = \frac{Opposite}{Hypotenuse}$

$\sin L = \frac{MN}{LN}$

Substitute values for MN and LN

$\sin L = \frac{6}{10}$

$\sin L = 0.60$

Solving (b): $tan\ N$

$tan\ N = \frac{Opposite}{Adjacent}$

$tan\ N = \frac{LM}{MN}$

Substitute values for LM and MN

$tan\ N = \frac{8}{6}$

$tan\ N = 1.33$

Solving (c): $\cos L$

$\cos L = \frac{Adjacent}{Hypotenuse}$

$\cos L = \frac{LM}{LN}$

Substitute values for LN and LM

$\cos L = \frac{8}{10}$

$\cos L = 0.80$

Solving (d): $\sin N$

$\sin N = \frac{Opposite}{Hypotenuse}$

$\sin N = \frac{LM}{LN}$

Substitute values for LM and LN

$\sin N = \frac{8}{10}$

$\sin N = 0.80$

7 0

3 years ago

A chord of a circular clock is 48 inches long, and its midpoint is 7 inches from the center of the circle. What is the radius of

Sphinxa [80]

ANSWER

The radius is 25 inches

EXPLANATION

From the diagram, the radius of the circle is AC.

From the Pythagoras Theorem,

${r}^{2} = {7}^{2} + {24}^{2}$

$r^{2} = 49 + 576$

Simplify

$r^{2} = 625$

Take positive square root,

$r = \sqrt{625}$

$r = 25$

Hence the radius is 25 inches

8 0

3 years ago

supervisor records the repair cost for 25 randomly selected dryers. A sample mean of $93.36 and standard deviation of $19.95 are

Simora [160]

<h2><u>Answer with explanation:</u></h2>

The confidence interval for population mean (when population standard deviation is unknown) is given by :-

$\overline{x}-t^*\dfrac{s}{\sqrt{n}}< \mu$

, where n= sample size

$\overline{x}$ = Sample mean

s= sample size

t* = Critical value.

Given : n= 25

Degree of freedom : $df=n-1=24$

$\overline{x}= \$93.36$

$s=\ $19.95$

Significance level for 98% confidence interval : $\alpha=1-0.98=0.02$

Using t-distribution table ,

Two-tailed critical value for 98% confidence interval :

$t^*=t_{\alpha/2,\ df}=t_{0.01,\ 24}=2.4922$

⇒ The critical value that should be used in constructing the confidence interval = 2.4922

Then, the 95% confidence interval would be :-

$93.36-(2.4922)\dfrac{19.95}{\sqrt{25}}< \mu$

$=93.36-9.943878< \mu$

$=93.36-9.943878< \mu$

$=83.416122< \mu$

Hence, the 98% confidence interval for the mean repair cost for the dryers. = $83.4161$

4 0

3 years ago