Answer:
2a) -2
b) 8
Step-by-step explanation:
<u>Equation of a parabola in vertex form</u>
f(x) = a(x - h)² + k
where (h, k) is the vertex and the axis of symmetry is x = h
2 a)
Using the equation of a parabola in vertex form, a parabola with vertex (2, -6):
f(x) = a(x - 2)² - 6
If one of the x-axis intercepts is 6, then
f(6) = 0
⇒ a(6 - 2)² - 6 = 0
⇒ 16a - 6 = 0
⇒ 16a = 6
⇒ a = 6/16 = 3/8
So f(x) = 3/8(x - 2)² - 6
To find the other intercept, set f(x) = 0 and solve for x:
f(x) = 0
⇒ 3/8(x - 2)² - 6 = 0
⇒ 3/8(x - 2)² = 6
⇒ (x - 2)² = 16
⇒ x - 2 = ±4
⇒ x = 6, -2
Therefore, the other x-axis intercept is -2
b)
Using the equation of a parabola in vertex form, a parabola with vertex (2, -6):
f(x) = a(x - 2)² - 6
If one of the x-axis intercepts is -4, then
f(-4) = 0
⇒ a(-4 - 2)² - 6 = 0
⇒ 36a - 6 = 0
⇒ 36a = 6
⇒ a = 6/36 = 1/6
So f(x) = 1/6(x - 2)² - 6
To find the other intercept, set f(x) = 0 and solve for x:
f(x) = 0
⇒ 1/6(x - 2)² - 6 = 0
⇒ 1/6(x - 2)² = 6
⇒ (x - 2)² = 36
⇒ x - 2 = ±6
⇒ x = 8, -4
Therefore, the other x-axis intercept is 8
Resposta:
Primer rectangle:
Amplada = 11
Longitud = 14
Segon rectangle:
Amplada = 12
Longitud = 15
Tercer rectangle:
Amplada = 13
Longitud = 16
Explicació pas a pas:
Donat que:
Primer rectangle:
Amplada = x
Longitud = x + 3
2n rectangle:
Augment de la dimensió d'1 cm respecte al primer rectangle;
Amplada = x + 1
Longitud = x + 4
3r rectangle:
Augment de la dimensió de 2 cm respecte al primer rectangle;
Amplada = x + 2
Longitud = x + 5
Suma dels tres perímetres del rectangle:
Perímetre d'un rectangle: 2 (l + O)
Primer rectangle:
2 (x + x + 3) = 2 (2x + 3) = 4x + 6
2n:
2 (x + 1 + x + 4) = 2 (2x + 5) = 4x + 10
3r:
2 (x + 2 + x + 5) = 2 (2x + 7) = 4x + 14
Suma de perímetres = 162
(4x + 6 + 4x + 10 + 4x + 14) = 162
12x + 30 = 162
12x = 162 - 30
12x = 130
x = 11
Per tant,
Primer rectangle:
Amplada = 11
Longitud = 11 + 3 = 14
2n rectangle:
Amplada = 11 + 1 = 12
Longitud = 11 + 4 = 15
3r rectangle:
Amplada = 11 + 2 = 13
Longitud = 11 + 5 = 16
Answer:
13
Step-by-step explanation:
Answer:
Answer: -0.008
Step-by-step explanation:
Hope this helped!
