SOLUTION: Suppose f(x) = (x-7)(x+4).
(a) For which values of x is the function f(x) positive? Enter your answer using inequalities.
help (inequalities)
(B) For which values of x i
Algebra ->
Quadratic Equations and Parabolas
-> SOLUTION: Suppose f(x) = (x-7)(x+4).
(a) For which values of x is the function f(x) positive? Enter your answer using inequalities.
help (inequalities)
(B) For which values of x i
Log On
Question 924062: Suppose f(x) = (x-7)(x+4).
(a) For which values of x is the function f(x) positive? Enter your answer using inequalities.
help (inequalities)
(B) For which values of x is the function f(x) negative? Enter your answer using inequalities.
help (inequalities)
need part b please already got part a Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website! find the points where the value is equal to 0.
that would be at x = 7 and x = -4
now look at the intervals that are created.
there will be 3.
first interval is when x is smaller than -4
second interval is when x is between -4 and 7
third interval is when x is greater than 7.
now pick a point in each interval and evaluate the expression.
when x = -5, (-5-7)(-5+4) = -12*-1 = 12 = positive.
when x = 0, (0-7)(0+4) = -7*4 = -28 = negative.
when x = 10, (10-7)(10+4) = 3*14 = 42 = positive
the function is positive when x < -4 or x > 7
the function is negative when x > -4 and x < 7 which can be written as 4 < x < 7
