12-e <-2<br>solution???

Determine the value of k for which -3x^2+12x+k=0 has no real roots.

Crazy boy [7]

Answer:

K<-12

Step-by-step explanation:

+ For that, we need the delta negatif.

+ The delta= b^2-4ac=12^2-4(-3)(k)=144+12k<0

Then, 12k<-144 (divise both sides by 12)

we have k<-12

Or an other way:

-3x^2+12x+k=0 (divise both sides by -3)

x^2-4x-k/3=0

x^2-4x+4 -4-k/3=0

(x-2)^2=4+k/3

Now , we need 4+k/3<0, k/3<-4 or k<-12

Hope you understand.

4 0

3 years ago

The point (9, 12) is on the terminal side of an angle in standard position.

Alexxandr [17]

Answer:D

Step-by-step explanation:

3 0

3 years ago

Si una llave vierte 6 1/3 litros de agua por minuto, ¿cuánto tiempo tardará en llenar un depósito de 88 2/3 litros de capacidad?

Ierofanga [76]

Answer: 14 minutes

Step-by-step explanation:

Given: A tap pours $6\dfrac13$ liters of water per minute.

To find : Time taken to fill an $88 \dfrac23$ liters capacity tank.

which is given by :-

Time = $88 \dfrac23\div 6\dfrac13$ minutes

$=\dfrac{3\times88+2}{3}\div\dfrac{3\times6+1}{3}$ minutes

$=\dfrac{266}{3}\div \dfrac{19}{3}$ minutes

$=\dfrac{266}{3}\times\dfrac{3}{19}$ minutes

$=\dfrac{266}{19}=14\text{ minutes}$

Hence, it will take 14 minutes to fill an $88 \dfrac23$ liters capacity tank.

6 0

3 years ago

A random sample of 16 students selected from the student body of a large university had an average age of 25 years. We want to d

kenny6666 [7]

Answer:

$z=\frac{25-24}{\frac{2}{\sqrt{16}}}=2$

$p_v =2*P(Z>2)=0.0455$

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the true mean differs from 24 at 5% of significance

Step-by-step explanation:

Data given and notation

$\bar X=25$ represent the sample mean

$\sigma=2$ represent the sample population deviation for the sample

$n=16$ sample size

$\mu_o =24$ represent the value that we want to test

$\alpha=0.05$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is different from 24, the system of hypothesis would be:

Null hypothesis: $\mu = 24$

Alternative hypothesis: $\mu \neq 24$

If we analyze the size for the sample is < 30 but we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$z=\frac{25-24}{\frac{2}{\sqrt{16}}}=2$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(Z>2)=0.0455$

Conclusion

If we compare the p value and the significance level given $\alpha=0.05$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and we can conclude that the true mean differs from 24 at 5% of significance

6 0

4 years ago

PLEASE HELP AS SOON AS POSSIBLE WILL GIVE BRAINLIEST

allsm [11]

The answer and work is in the SS below

3 0

3 years ago

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