9514 1404 393
Answer:
"complete the square" to put in vertex form
Step-by-step explanation:
It may be helpful to consider the square of a binomial:
(x +a)² = x² +2ax +a²
The expression x² +x +1 is in the standard form of the expression on the right above. Comparing the coefficients of x, we see ...
2a = 1
a = 1/2
That means we can write ...
(x +1/2)² = x² +x +1/4
But we need x² +x +1, so we need to add 3/4 to the binomial square in order to make the expressions equal:

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Another way to consider this is ...
x² +bx +c
= x² +2(b/2)x +(b/2)² +c -(b/2)² . . . . . . rewrite bx, add and subtract (b/2)²*
= (x +b/2)² +(c -(b/2)²)
for b=1, c=1, this becomes ...
x² +x +1 = (x +1/2)² +(1 -(1/2)²)
= (x +1/2)² +3/4
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* This process, "rewrite bx, add and subtract (b/2)²," is called "completing the square"—especially when written as (x-h)² +k, a parabola with vertex (h, k).
9514 1404 393
Answer:
5) 112°
6) 40°
Step-by-step explanation:
5) The angle E or ? is half the sum of the intercepted arcs:
? = (130° +94°)/2 = 112°
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6) The angle D is half the difference of the intercepted arcs:
? = (135° -55°)/2 = 40°
Usando el teorema de altura El teorema de altura relaciona la altura (h) de un triángulo rectángulo (ver figura) y los catetos de dos triángulos que son semejantes al anterior ABC, al trazar la altura (h) sobre la hipotenusa. De manera que e<span>n todo </span>triángulo rectángulo, la altura (h<span>) relativa a la </span>hipotenusa<span> es la </span>media geométrica<span> de las dos proyecciones de los </span>catetos<span> sobre la </span>hipotenusa<span> (</span>n<span> y </span>m<span>). Es decir, se cumple que:
</span>

Dado que el problema establece <span>construir un segmento cuya longitud sea media proporcional entre dos segmentos de 4 y 9 cm, entonces, digamos que n = 4cm y m = 9cm tenmos que:
</span>

De donde:
¿Cómo se podria construir si los segmentos son de a cm y b cm?
Si los segmentos son de a y b cm entonces a y b son parámetros que pueden tomar cualquier valor positivo siempre que se cumpla que:

Answer:
12
Step-by-step explanation:
We can see that the base TA is 4, and the second base RS is 2. We can see that the height is 4. The area of a trapezoid is:

Using this, we can substitute, and get:

Hope it helps!!