Question

Y=98x^2+56x+8 find the x intercept rewriting the function in intercept form

Answer 1

`\sf \left((-2)/(7) , 0\right) ; ~~ \left((-2)/(7) , 0\right)`

Explanation:

Rewrite the function in intercept form: f(x) = a (x + m)(x +n), where a ≠ 0

y = 98x² + 56x + 8

= 2*49x² + 2*28x + 2*4

Take the common variable 2 out of the equation,

=2*(49x² + 28x + 4)

Now, factorize,

= 2 * [ (7x)² + 2 * 7x * 2 + 2²]

It is in (a + b)² form. (a + b)² = a² + b² + 2ab. Here a = 7x and b = 2

= 2 * (7x + 2)²

y = 2 (7x + 2) (7x + 2)

At x-intercept, y = 0

7x + 2 = 0

7x = -2

`\sf x = (-2)/(7)`

Answer:

x - intercept:
`\sf \left((-2)/(7) , 0\right) ; ~~ \left((-2)/(7) , 0\right)`