Answer:x = +- 2 and x = +- √2
Step-by-step explanation:
Let's covert x^4 - 6x^2 + 8 = 0 into quadratic equation.
Let e = x ^ 2
So,
(x^2)^2 - 6x^2 + 8 = 0
e^2 - 6e + 8 = 0
e^2 - 4e - 2e + 8 = 0
e( e - 4 ) -2( e - 4 )
( e - 4 ) ( e - 2 ) = 0
Either,
e - 4 = 0
x^2 - 4 = 0 ( REMEMBER THAT e= x^2)
x^2 = 4
x = +- 2
Or,
e - 2 = 0
x^2 = 2
x = +- √2
Answer:
Step-by-step explanation:
From the information given:
mean life span of a brand of automobile = 35,000
standard deviation of a brand of automobile = 2250 miles.
the z-score that corresponds to each life span are as follows.
the standard z- score formula is:
For x = 34000
z = −0.4444
For x = 37000
z = 0.8889
For x = 3000
z = -2.222
From the above z- score that corresponds to their life span; it is glaring that the tire with the life span 30,000 miles has an unusually short life span.
For x = 30,500
z = -2
P(z) = P(-2)
Using excel function (=NORMDIST -2)
P(z) = 0.022750132
P(z) = 2.28th percentile
For x = 37250
z = 1
Using excel function (=NORMDIST 1)
P(z) = 0.841344746
P(z) = 84.14th percentile
For x = 35000
z = 0
Using excel function (=NORMDIST 0)
P(z) = 0.5
P(z) = 50th percentile
3x² - 2x + 7 = 0.
Using method of completing the square.
3x² - 2x = 0 - 7
3x² - 2x = -7 Divide through by 3.
x² - 2/3x = -7/3 ...........(d)
Coefficient of x = -2/3, half of it = 1/2*-2/3 = -1/3 square of it = (-1/3)² = 1/9
We add (1/9) to both sides of equation (d)
<span>x² - 2/3x = -7/3
</span>
<span>x² - 2/3x + 1/9 = -7/3 + 1/9
We factorize it by making using of half of the coefficient, -1/3
</span>
(x - 1/3)² = -7/3 + 1/9
<span>(x - 1/3)² = -20/9
</span>
That's the answer as asked by the question. -20/9
Answer:
5
Step-by-step explanation:
1 ÷ 1/5= 1 x 5/1 =5
I hope im right!!
Answer:
[2,4]
Step-by-step explanation: