for the quadratic function f(x)= -x² - 2x, answer parts (a) through (f). (a) find the vertex and the axis of…

for the quadratic function f(x)= -x² - 2x, answer parts (a) through (f). (a) find the vertex and the axis of symmetry of the quadratic function, and determine whether the graph is concave up or concave down. the vertex is . (type an ordered pair, using integers or fractions.)
Answer
Answer:
(-1, 1)
Explanation:
Step1: Identify coefficients
For $f(x)=-x^{2}-2x$, $a = - 1$, $b=-2$, $c = 0$.
Step2: Find x - coordinate of vertex
Use formula $x=-\frac{b}{2a}$. Substitute $a=-1$ and $b = - 2$: $x=-\frac{-2}{2\times(-1)}=-1$.
Step3: Find y - coordinate of vertex
Substitute $x = - 1$ into $f(x)$: $f(-1)=-(-1)^{2}-2\times(-1)=-1 + 2=1$.
Step4: Determine axis of symmetry
Axis of symmetry is $x=-1$ (same as x - coordinate of vertex).
Step5: Determine concavity
Since $a=-1<0$, the graph is concave down.