factorise (2x) ^ 2 + 6x ^ 2 + (3/4) ^ 2
Answers
Step-by-step explanation:
4x^2+6x^2+(9/16)
10x^2+9/16
Answer:
x =(3-√13)/2=-0.303
Step-by-step explanation:
(2x2 - 6x) - 2 = 0
2x2 - 6x - 2 = 2 • (x2 - 3x - 1)
The first term is, x2 its coefficient is 1 .
The middle term is, -3x its coefficient is -3 .
The last term, "the constant", is -1
Step-1 : Multiply the coefficient of the first term by the constant 1 • -1 = -1
Step-2 : Find two factors of -1 whose sum equals the coefficient of the middle term, which is -3 .
-1 + 1 = 0
2 • (x2 - 3x - 1) = 0
y = 1.0 * 1.50 * 1.50 - 3.0 * 1.50 - 1.0
or y = -3.250
Root plot for : y = x2-3x-1
Axis of Symmetry (dashed) {x}={ 1.50}
Vertex at {x,y} = { 1.50,-3.25}
x -Intercepts (Roots) :
Root 1 at {x,y} = {-0.30, 0.00}
Root 2 at {x,y} = { 3.30, 0.00}
Add 9/4 to both sides of the equation :
On the right hand side we have :
1 + 9/4 or, (1/1)+(9/4)
The common denominator of the two fractions is 4 Adding (4/4)+(9/4) gives 13/4
So adding to both sides we finally get :
x2-3x+(9/4) = 13/4
Adding 9/4 has completed the left hand side into a perfect square :
x2-3x+(9/4) =
(x-(3/2)) • (x-(3/2)) =
(x-(3/2))2
Things which are equal to the same thing are also equal to one another. Since
x2-3x+(9/4) = 13/4 and
x2-3x+(9/4) = (x-(3/2))2
then, according to the law of transitivity,
(x-(3/2))2 = 13/4
x2 - 3x - 1 = 0
has two solutions:
x = 3/2 + √ 13/4
or
x = 3/2 - √ 13/4
Note that √ 13/4 can be written as
√ 13 / √ 4 which is √ 13 / 2
- B ± √ B2-4AC
x = ————————
2A
In our case, A = 1
B = -3
C = -1
Accordingly, B2 - 4AC =
9 - (-4) =
13
Applying the quadratic formula :
3 ± √ 13
x = —————
2
√ 13 , rounded to 4 decimal digits, is 3.6056
So now we are looking at:
x = ( 3 ± 3.606 ) / 2
Two real solutions:
x =(3+√13)/2= 3.303
or:
x =(3-√13)/2=-0.303