Question

What is the minimum or maximum?
y= -x^2-x-1

Answer 1

is a parabola, the leading coefficient, that is from \(\bf -x^2\) is negative, so it's going downwards

so it'll look like

the HIGHEST point will be where the vertex is at
you can get the y-coordinate for the vertex with \(\bf c-\cfrac{b^2}{4a}\)

Answer 2

i already got that. but i cant figure out the equation for y coordinate

Answer 3

sorry was... a bit elsewhere....
\(\bf \begin{array}{llll}
&a&b&c\\
y= -x^2-x-1 \implies y= &-1x^2&-1x&-1
\end{array}\\
c-\cfrac{b^2}{4a}\)

Answer 4

a, b and c, are just the coefficients

Answer 5

i got .25?

Answer 6

well, \(\bf c-\cfrac{b^2}{4a} \implies (-1)-\left(\cfrac{(-1)^2}{4(-1)}\right) \implies (-1)-\left(\cfrac{1}{-4}\right) \\\quad \\
\implies -1 + \cfrac{1}{4} \implies -\cfrac{4}{4}+\cfrac{1}{4} \implies -\cfrac{3}{4} = 0.75\)

Answer 7

woops, -0.75 for that matter, missed the - there

Answer 8

\(\bf -\cfrac{3}{4} = -0.75\)