Solve x2+4x=1 by Completing the square

Mathematics

1 answer:

Viefleur [7K]2 years ago

7 0

Answer:

x = -2 ±√5

Step-by-step explanation:

You want to complete the square by adding the square of half the coefficient of the linear term:

x^2 + 4x + (4/2)^2 = 1 + (4/2)^2

(x +2)^2 = 5 . . . . . simplify

x +2 = ±√5 . . . . . . take the square root

x = -2 ±√5 . . . . . . subtract 2. This is the solution.

For the problem in the picture, replace x with p in the above.

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1. Determine a rule that could be used to explain how the volume of a

Eva8 [605]

Answer:

See explanation

Step-by-step explanation:

Solution:-

- We will use the basic formulas for calculating the volumes of two solid bodies.

- The volume of a cylinder ( V_l ) is represented by:

$V_c = \pi *r^2*h$

- Similarly, the volume of cone ( V_c ) is represented by:

$V_c = \frac{1}{3}*\pi *r^2 * h$

Where,

r : The radius of cylinder / radius of circular base of the cone

h : The height of the cylinder / cone

- We will investigate the correlation between the volume of each of the two bodies wit the radius ( r ). We will assume that the height of cylinder/cone as a constant.

- We will represent a proportionality of Volume ( V ) with respect to ( r ):

$V = C*r^2$

Where,

C: The constant of proportionality

- Hence the proportional relation is expressed as:

V∝ r^2

- The volume ( V ) is proportional to the square of the radius. Now we will see the effect of multiplying the radius ( r ) with a positive number ( a ) on the volume of either of the two bodies:

$V = C*(a*r)^2\\\\V = C*a^2*r^2$

- Hence, we see a general rule frm above relation that multiplying the result by square of the multiple ( a^2 ) will give us the equivalent result as multiplying a multiple ( a ) with radius ( r ).

- Hence, the relations for each of the two bodies becomes:

$V = (\frac{1}{3} \pi *r^2*h)*a^2$