Reformatting the input :
Changes made to your input should not affect the solution:
(1): "m2" was replaced by "m^2".
Step by step solution :
Step 1 :
Equation at the end of step 1 :
(22m2 - 4m) - 1 = 0 Step 2 :
Trying to factor by splitting the middle term
2.1Factoring 4m2-4m-1
The first term is, 4m2 its coefficient is 4.
The middle term is, -4m its coefficient is -4.
The last term, "the constant", is -1
Step-1 : Multiply the coefficient of the first term by the constant 4•-1=-4
Step-2 : Find two factors of -4 whose sum equals the coefficient of the middle term, which is -4.
| -4 | + | 1 | = | -3 | ||
| -2 | + | 2 | = | 0 | ||
| -1 | + | 4 | = | 3 |
Observation : No two such factors can be found !!
Conclusion : Trinomial can not be factored
Equation at the end of step 2 :
4m2 - 4m - 1 = 0 Step 3 :
Parabola, Finding the Vertex:
3.1Find the Vertex ofy = 4m2-4m-1Parabolas have a highest or a lowest point called the Vertex.Our parabola opens up and accordingly has a lowest point (AKA absolute minimum).We know this even before plotting "y" because the coefficient of the first term,4, is positive (greater than zero).Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two x-intercepts (roots or solutions) of the parabola. That is, if the parabola has indeed two real solutions.Parabolas can model many real life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that object, thrown upwards, can reach. For this reason we want to be able to find the coordinates of the vertex.For any parabola,Am2+Bm+C,the m-coordinate of the vertex is given by -B/(2A). In our case the m coordinate is 0.5000Plugging into the parabola formula 0.5000 for m we can calculate the y-coordinate:
y = 4.0 * 0.50 * 0.50 - 4.0 * 0.50 - 1.0
or y = -2.000
Parabola, Graphing Vertex and X-Intercepts :
Root plot for : y = 4m2-4m-1
Axis of Symmetry (dashed) {m}={ 0.50}
Vertex at {m,y} = { 0.50,-2.00}
m-Intercepts (Roots) :
Root 1 at {m,y} = {-0.21, 0.00}
Root 2 at {m,y} = { 1.21, 0.00}
Solve Quadratic Equation by Completing The Square
3.2Solving4m2-4m-1 = 0 by Completing The Square.Divide both sides of the equation by 4 to have 1 as the coefficient of the first term :
m2-m-(1/4) = 0
Add 1/4 to both side of the equation :
m2-m = 1/4
Now the clever bit: Take the coefficient of m, which is 1, divide by two, giving 1/2, and finally square it giving 1/4
Add 1/4 to both sides of the equation :
On the right hand side we have:
1/4+1/4The common denominator of the two fractions is 4Adding (1/4)+(1/4) gives 2/4
So adding to both sides we finally get:
m2-m+(1/4) = 1/2
Adding 1/4 has completed the left hand side into a perfect square :
m2-m+(1/4)=
(m-(1/2))•(m-(1/2))=
(m-(1/2))2
Things which are equal to the same thing are also equal to one another. Since
m2-m+(1/4) = 1/2 and
m2-m+(1/4) = (m-(1/2))2
then, according to the law of transitivity,
(m-(1/2))2 = 1/2
We'll refer to this Equation as Eq. #3.2.1
The Square Root Principle says that When two things are equal, their square roots are equal.
Note that the square root of
(m-(1/2))2 is
(m-(1/2))2/2=
(m-(1/2))1=
m-(1/2)
Now, applying the Square Root Principle to Eq.#3.2.1 we get:
m-(1/2)= √ 1/2
Add 1/2 to both sides to obtain:
m = 1/2 + √ 1/2
Since a square root has two values, one positive and the other negative
m2 - m - (1/4) = 0
has two solutions:
m = 1/2 + √ 1/2
or
m = 1/2 - √ 1/2
Note that √ 1/2 can be written as
√1 / √2which is 1 / √2
It is customary to further simplify until the denominator is radical free.
This can be achieved here by multiplying both the nominator and the denominator by√2
Following this multiplication, the numeric value of 1 /√2remains unchanged, as it is multiplyed by √2/√2 which equals1OK, let's do it:
1 • √2 1 • √2
————————————— = ————————————
√2 • √2 2
Solve Quadratic Equation using the Quadratic Formula
3.3Solving4m2-4m-1 = 0 by the Quadratic Formula.According to the Quadratic Formula,m, the solution forAm2+Bm+C= 0 , where A, B and C are numbers, often called coefficients, is given by :
-B± √B2-4AC
m = ————————
2A In our case,A= 4
B= -4
C= -1 Accordingly,B2-4AC=
16 - (-16) =
32Applying the quadratic formula :
4 ± √ 32
m=—————
8Can √ 32 be simplified ?
Yes!The prime factorization of 32is
2•2•2•2•2
To be able to remove something from under the radical, there have to be 2 instances of it (because we are taking a square i.e. second root).
√ 32 =√2•2•2•2•2 =2•2•√ 2 =
±4 •√ 2
√ 2 , rounded to 4 decimal digits, is 1.4142
So now we are looking at:
m=(4±4• 1.414 )/8
Two real solutions:
m =(4+√32)/8=(1+√ 2 )/2= 1.207
or:
m =(4-√32)/8=(1-√ 2 )/2= -0.207
Two solutions were found :
- m =(4-√32)/8=(1-√ 2 )/2= -0.207
- m =(4+√32)/8=(1+√ 2 )/2= 1.207
