All categories

4 years ago

Using the quadratic formula, what is the value of x for x^2-4+5=0

Mathematics

1 answer:

PSYCHO15rus [73]4 years ago

4 0

value of x is: x= i and x= -i

Step-by-step explanation:

We need to find the value of x from $x^2-4+5=0$ using quadratic formula.

The term is: $x^2+1=0$

The quadratic formula is:

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

Where a = 1, b=0,c=1

Putting values:

$x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}\\x=\frac{0\pm\sqrt{(0)^2-4(1)(1)}}{2(1)}\\x=\frac{\pm\sqrt{-4}}{2}\\x=\frac{\pm2i}{2}\\x=\pm i$

So, value of x is: x= i and x= -i

Keywords: Quadratic formula

Learn more about quadratic formula at:

#learnwithBrainly

You might be interested in

Jake has a bag of 50 beads, some of which are blue and the remaining are green. Jake randomly pulls out a bead from the bag, rec

kobusy [5.1K]

Answer:

Step-by-step explanation:

3 0

3 years ago

Find the coordinates of point T

KATRIN_1 [288]

Answer:

(2,0)

Step-by-step explanation:

(6-(10-6), 4- (8-4))

8 0

3 years ago

The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM. If 188 sixth graders

Anna007 [38]

Answer:

0.1836 = 18.36% probability that the sample mean would differ from the population mean by greater than 1.46 WPM

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

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

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

The mean number of words per minute (WPM) read by sixth graders is 84 with a standard deviation of 15 WPM.

This means that $\mu = 84, \sigma = 15$

Sample of 188

This means that $n = 188, s = \frac{15}{\sqrt{188}}$

What is the probability that the sample mean would differ from the population mean by greater than 1.46 WPM?

Greater than 84 + 1.46 = 85.46 or less than 84 - 1.46 = 82.54. Since the normal distribution is symmetric, these probabilities are equal, so we find one of them and multiply by 2.

Probability is is less than 82.54.

P-value of Z when X = 82.54. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$