how i can find min and mix value of a function? and gernal formula

Question

anonymous · Answer

hi, 
Okay to find the maximum or minimum value of a function you can use the formula:

$$x = -b / 2a$$

With the function $$y=x²+12x-7... ( y = ax^2 + bx + c )$$
$$b = 12$$
$$a = 1$$

 those numbers into the formula...
$$x = -b / 2a$$
$$x = -12 / 2(1) $$simplify!
$$x = -12 / 2$$
$$x = -6$$

Now you have the x coordinate for the minimum for this function. If you need to find the y coordinate just plug -6 into the original equation.
Minimum @ $$( -6, 43 )$$

campbell_st · Answer

find the 1st and second derivatives... 

let the 1st derivative = 0 and solve.... this gives stationary points.... 

test the stationary points in the 2nd derivative.. 

f"(c) > 0 a minimum at c
f"(c)<0 a maximum at c