Answer:

Step-by-step explanation:
<u>Funciones Trigonométricas</u>
La identidad principal en trigonometría es:

Si sabemos que A es un ángulo agudo (que mide menos de 90°), su seno y coseno son positivos.
Dado que Sen A = 4/5, calculamos el coseno:

Sustituyendo:




Tomando raíz cuadrada:

La tangente se define como:

Substituyendo:


Answer:
x = - 5, x = 4
Step-by-step explanation:
Given
f(x) = x² + x - 20
To find the zeros equate f(x) to zero, that is
x² + x - 20 = 0
Consider the factors of the constant term ( - 20) which sum to give the coefficient of the x- term ( + 1)
The factors are + 5 and - 4, since
5 × - 4 = - 20 and + 5 - 4 = + 1, hence
(x + 5)x - 4) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 5 = 0 ⇒ x = - 5
x - 4 = 0 ⇒ x = 4
Answer:
45
Step-by-step explanation:
AEF is a similar triangle to ABC. that means it has the same angles, and the sides (and all other lines in the triangle) are scaled from the ABC length to the AEF length by the same factor f.
now, what is f ?
we know this from the relation of AC to FA.
FA = 12 mm
AC = 12 + 28 = 40 mm
so, going from AC to FA we multiply AC by f so that
AC × f = FA
40 × f = 12
f = 12/40 = 3/10
all other sides, heights, ... if ABC translate to their smaller counterparts in AEF by that multiplication with f (= 3/10).
the area of a triangle is
baseline × height / 2
aABC = 500
and because of the similarity we don't need to calculate the side and height in absolute numbers. we can use the relative sizes by referring to the original dimensions and the scaling factor f.
baseline small = baseline large × f
height small = height large × f
we know that
baseline large × height large / 2 = 500
baseline large × height large = 1000
aAEF = baseline small × height small / 2 =
= baseline large × f × height large × f / 2 =
= baseline large × height large × f² / 2 =
= 1000 × f² / 2 = 500 × f² = 500 ×(3/10)² =
= 500 × 9/100 = 5 × 9 = 45 mm²
Answer:
There are a total of 2 hours and 50 min.
Step-by-step explanation:
1 hour = 60 min
60 x 2 = 120 min
60 x 3 = 180 min - too much
so take away 10 from 180 min to get 170