Finding Points A and B on the Quadratic Graph of f(x) = -x^2 + 5x + 6

Question

The following function has been graphed below:

f(x)=x2+5x+6 f(x)=-x^2+5x+6

Calculate points A and B.

BBBAAACCC

Video Solution

Solution Steps

00:00 Find the coordinates of points A,B
00:03 Note that points A,B are the intersection points with the X-axis
00:10 At the intersection points with X-axis, the Y value must = 0
00:15 Substitute Y = 0 and solve for X values
00:28 Break down into trinomial
00:32 This is the corresponding trinomial
00:36 Find what zeros each factor in the product
00:41 This is one solution
00:48 This is second solution
00:52 And this is the solution to the question

Step-by-Step Solution

To solve for the x-intercepts of the function f(x)=x2+5x+6 f(x) = -x^2 + 5x + 6 , we will find the roots of the quadratic equation x2+5x+6=0 -x^2 + 5x + 6 = 0 .

Let's attempt to factor this quadratic equation first. Rewrite the equation as follows:

x2+5x+6=0 -x^2 + 5x + 6 = 0 .

To factor, we look for two numbers that multiply to 6-6 (the product of aa and cc, where a=1a = -1 and c=6c = 6) and add to 55 (the middle coefficient bb).

The numbers that satisfy this condition are 1-1 and 66.

Thus, the quadratic can be factored as:

(x6)(x+1)=0(x - 6)(x + 1) = 0.

Setting each factor equal to zero gives us:

x6=0x - 6 = 0 or x+1=0x + 1 = 0.

Solving these equations, we find:

x=6x = 6 and x=1x = -1.

Thus, the points A and B, the x-intercepts of the function, are:

(1,0)(-1, 0) and (6,0) (6, 0).

Therefore, the solution to the problem is (1,0),(6,0)(-1, 0), (6, 0).

Answer

(1,0),(6,0) (-1,0),(6,0)