the symmetrical axis of a quadratic function graphic is x=4. if the graphic passes points (1,8) and (6,3) then the extreme value of the quadratic function is?
A. maximum 3
B. maximum 2
C. minimum 1
D. minimum 2
E. minimum 2

Question

the symmetrical axis of a quadratic function graphic is x=4. if the graphic passes points (1,8) and (6,3) then the extreme value of the quadratic function is?
A. maximum 3
B. maximum 2
C. minimum 1
D. minimum 2
E. minimum 2

vishweshshrimali5 · Answer

Did you give it a try ?

vishweshshrimali5 · Answer

@dinisha ?

anonymous · Answer

i dunno how start!!

vishweshshrimali5 · Answer

Okay see, I am going to draw a graph for you:

|dw:1403014042217:dw|

Approximately the curve is symmetric about x = 4.

vishweshshrimali5 · Answer

See this link:

www.mathopenref.com/quadvertexexplorer.html

the equation of the curve would be like:

$$\large{y = a(x-4)^2 + k}$$

vishweshshrimali5 · Answer

Now, this curve passes through (1,8) and (6,3).
So, these values must satisfy this equation.

vishweshshrimali5 · Answer

Do you understand till this step @dinisha ?

anonymous · Answer

i cant open the link you gave??

vishweshshrimali5 · Answer

No problem. Forget that link.

It just says that this equation :

$$\large{y = a(x-h)^2 + k}$$

represent a parabola symmetric about x = h.

vishweshshrimali5 · Answer

So, now you have an equation and its two solutions. So, can you find out the value of a and k ?