Identify the vertex for
f(x)=4x^2-8x-4

Step-by-step explanation:

You could complete the square to do this, or you could just evaluate the h coordinate using the simple formula

then find k by subbing that h value into the equation for x to find y which is the same as k.  In our quadratic, a = 4, b = -8, and c = -4.

Now sub that value into the quadratic to find y (k):

The vertex of the quadratic is (1, -8)

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15