Question

Can someone answer question 2a and b only please

Answer 1

Answer:

2a)  -2

b) 8

Step-by-step explanation:

Equation of a parabola in vertex form

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