the graph of a quadratic function (parabola) has x-intercepts -1 and 3 and a range consisting of all numbers less than or equal to 4. Determine an expression for the function.

Question

anonymous · Answer

this is a quadratic which opens downwards with a vertex  ( a maxm.) at f(x) = 4

anonymous · Answer

so how would i write that as a function?

anonymous · Answer

-(x+3)(x-1)
= -x^2+2x +3
negative because graph opens downwards

anonymous · Answer

do i have to do something with the 4 in the equation?

anonymous · Answer

yes u have to skrew it up...

anonymous · Answer

and den fuk it up

anonymous · Answer

sorry the first line should be 
-(x-3)(x+1)
second line was correct

anonymous · Answer

you ok with that? do you see why 1 and 3 are in the brackets?

anonymous · Answer

- because they are the x intercepts on the graph of the function when value of function = 0

anonymous · Answer

r u there?

anonymous · Answer

yes! sorry

anonymous · Answer

i see that! i just thought the 4 was supposed to be in the equation also