Write the equation in standard form of the quadratic that has a root of (3,0) and a vertex at (1,-4), then list out the values of a, b and c.

a = 1, b = -2, c = -3

Step-by-step explanation:

The equation in factored form shows the roots with the "r" and "s" variables. Note that they are written negative "r" and negative "s" in the formula.

y = a(x - r)(x - s)

The vertex is always halfway between the two roots.

<[root][vertex][root]>

The vertex is at x = 1, and one root is at x = 3. The other root is at x = -1.

Write the equation in factored form to show the two roots.

y = a(x - 3)(x + 1)

Substitute the vertex (1, -4) into the equation. The point is written (x, y).

-4 = a(1 - 3)(1 + 1)

Solve for "a".

-4 = a(-2)(2)      Simplify within the brackets

-4 = -4a          Multiply -2 and 2. Divide both sides by -4

a = 1             Solved for "a" (and kept the variable on the left side).

Substitute a = 1 back into the formula.

y = a(x - 3)(x + 1)

y = 1(x - 3)(x + 1)

We don't have to write multiplied by 1 though, because anything multiplied by 1 is itself.

y = (x - 3)(x + 1)

Since we are looking for "a", "b", and "c", find the equation in standard form.

y = ax² + bx + c

To change factored form into standard form, expand the brackets.

y = (x - 3)(x + 1)

y = x² + x - 3x - 3

y = x² - 2x - 3

Compare the expanded equation to y = ax² + bx + c

∴ a = 1, b = -2, c = -3

2 x t divided by n

step-by-step explanation:

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)