1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
marin [14]
1 year ago
13

What are the solutions of the equation x^4-9x^2+8=0? Use u substitution to solve.

Mathematics
1 answer:
vodka [1.7K]1 year ago
4 0

Answer:

The answer is the second option

Step-by-step explanation:

Let u=x^2.

( {x}^{2} ) {}^{2}  - 9( {x}^{2} ) + 8( {x}^{2} ) {}^{0}

{u}^{2}  - 9u + 8

(u - 1)(u - 8)

u = 1

u = 8

Set this equal to x^2

{x}^{2}  = 1

x = 1

or

x =  - 1

{x}^{2}  = 8

x = 2 \sqrt{2}

or

x =  - 2 \sqrt{2}

You might be interested in
What is 15% of 75.50 and how did you get it
bekas [8.4K]
A percentage can just be written as a decimal where 100% = 1.00

15% = 0.15

75.5 * 0.15 = 11.325

You just multiply.
8 0
2 years ago
Read 2 more answers
After reading ¾ of a magazine on Sunday, 0.2 of the remainder on Monday, and 10 pages on Tuesday, Michael still had to read 42 p
icang [17]

Answer:

3 /4 of 2 is the answer to the question

3 0
2 years ago
Using traditional methods, it takes 10.1 hours to receive a basic driving license. A new license training method using Computer
Law Incorporation [45]

Answer:

We need to conduct a hypothesis in order to check if the technique performs differently than the traditional method, the system of hypothesis would be:  

Null hypothesis:\mu =10.1  

Alternative hypothesis:\mu \neq 10.1

t=\frac{10.5-10.1}{\frac{1.4}{\sqrt{12}}}=0.990    

p_v =2*P(t_{(11)}>0.990)=0.343    

If we compare the p value and the significance level given \alpha=0.1 we see that p_v>\alpha so we can conclude that we have enough evidence to FAIL  reject the null hypothesis, so we can't conclude that the technique performs differently than the traditional method at 10% of signficance.  

Step-by-step explanation:

Data given and notation  

\bar X=10.5 represent the sample mean

s=1.4 represent the sample standard deviation

n=12 sample size  

\mu_o =10.1 represent the value that we want to test

\alpha=0.1 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 technique performs differently than the traditional method, the system of hypothesis would be:  

Null hypothesis:\mu =10.1  

Alternative hypothesis:\mu \neq 10.1  

If we analyze the size for the sample is < 30 and we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:  

t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}  (1)  

t-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:  

t=\frac{10.5-10.1}{\frac{1.4}{\sqrt{12}}}=0.990    

P-value

The first step is calculate the degrees of freedom, on this case:  

df=n-1=12-1=11  

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

p_v =2*P(t_{(11)}>0.990)=0.343  

Conclusion  

If we compare the p value and the significance level given \alpha=0.1 we see that p_v>\alpha so we can conclude that we have enough evidence to FAIL  reject the null hypothesis, so we can't conclude that the technique performs differently than the traditional method at 10% of signficance.  

7 0
3 years ago
Harold has been hired as a salesman. He is paid a flat rate of $375 each week and earns an additional $14.25 commission for each
Andru [333]
The answer is
c. \: y = 14.25h + 375
5 0
3 years ago
A survey of 398 children given at a local elementary school showed that 175 like chocolate ice cream, 225 like pistachio ice cre
Maru [420]
225-175=50
175-50=125
125 chidren liked both chocolate and pistachio ice cream.
Check: 398-123=275
275-125=150
225-125=100
175-125=50
100+50=150
150-150=0
3 0
3 years ago
Other questions:
  • Lawrence just got a $1,500 bonus and is debating between buying a new computer for $700 and buying a home theater for $1,200. He
    14·2 answers
  • Sofia wants to place a sticker 2 ½ inches long in the center of a switch box that is 3 ¾ inches wide. About how far from the edg
    8·1 answer
  • A factory has two bottle filling machines, which run at the same time. Machine B fills bottles at a rate of x, which is 1.5 time
    11·1 answer
  • Mrs William has a prized box with different colored tickets. Each ticket results in different type of prize.
    12·1 answer
  • Which is a variable expression for the word phrase?
    9·1 answer
  • If AD=8 and BD=4, what is the length of DC⎯⎯⎯⎯⎯⎯?
    6·1 answer
  • What is 23.826 correct to two decimal places
    10·1 answer
  • Solve x+14=16<br> What is x?
    10·2 answers
  • A stadium has 47,000 seats. Seats sell for $42 in Section A, $36 in Section B, and $30 in Section C. The number of seats in Sect
    11·1 answer
  • The SAT is the most widely used test in the undergraduaté admissions process, Scores on the math portion of the SAT are believed
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!