-x^2-7x+9 find the vertex

Question

amistre64 · Answer

the x component of the vertex is the opposite of the middle number divided by 2

amistre64 · Answer

-(-7)/2 = 7/2; now use that to find the value of the function

amistre64 · Answer

-(7/2)^2 -7(7/2) +9 = ?

amistre64 · Answer

i get -27.75

amistre64 · Answer

so vertex = ($\frac{7}{2},\frac{-111}{4}$) maybe?

anonymous · Answer

the correct answer was (7/2,85/4)

amistre64 · Answer

hmm ..... i must miss placed a negative someplace

anonymous · Answer

here is another one -x^2-7x+7

amistre64 · Answer

-x^2-7x+9; Vx = 7/-2  if i see it right; you sure the correct answer doesnt start with -7/2?

anonymous · Answer

oops the new problem is -x^2-x+7

amistre64 · Answer

-(x^2 +x -7) = y

x^2 +x -7 = -y

x^2 +x = -y+7

x^2 +x +(1/2)^2 = -y +7 +(1/2)^2

(x+1/2)^2 = -y +(29/4)

-(x+1/2)^2 = y - (29/4)

y = -(x+(1/2))^2 + (29/4)

vertex = (1/2, 29,4) maybe?

anonymous · Answer

not correct

amistre64 · Answer

either you got a broken program; or someone broke the math today :)

anonymous · Answer

correct answer was -1/2,29/4

amistre64 · Answer

thiiiissss close; its the negative in front that is throwing me off ... bummer

amistre64 · Answer

wolfram says my math was right; I just interpreted it wrong afterwards