Welcome :: Homework Help and Answers :: Mathskey.com
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,459 questions

17,854 answers

1,446 comments

811,138 users

please helppppp! please

0 votes
draw an acurate graph of the quadratic function y=x^2 -7x + 10 on the grid.fill in the table of values for five critical points (vertex,x-intercepts(s),y intercepts,and the symmetrical point with the y-intercept) then answer

a) explain how to use your graph to find the solution to the quadratic equation x^2 -7x + 10 = 0

b) show how to check the answers you obtained from the graph to determine whether you have the correct answers.

Thanks.
asked Oct 29, 2014 in PRECALCULUS by anonymous

1 Answer

0 votes

Note :

To graph a quadratic function follow the steps :

Step 1 : Find the equation of the axis of symmetry.

Step 2 : Find vertex, and determine weather it is a maximum or minimum.

Step 3 : Find the y and x - intercepts.

Step 4 : Use symmetry to find additional points on the graph, if necessary.

Step 5 : Connect the points with a smooth curve.

The function is f(x) = y = x2 - 7x + 10.

The standard form of quadratic function is f(x) = ax2 + bx + c.

Step 1 :

Find the axis of symmetry :

Formula for the equation of the axis of symmetry:  x = - b/2a.

Substitute the values of b = - 7 and a = 1 in the formula, x = - b/2a.

x = - (- 7)/2(1) = 7/2.

The equation for the axis of symmetry is x = 7/2.

Step 2 :

Find the vertex :

To find the vertex, use the value of equation for the axis of symmetry as the  x - coordinate of the vertex.

To find the y - coordinate, substitute the value of x = 7/2 in the original function, y = x2 - 7x + 10.

y = (7/2)2 - 7(7/2) + 10

y = 49/4 - 49/2 + 10

y = - 9/4.

The vertex is (7/2, - 9/4).

Determine whether the function has maximum or minimum value :

The value of a = 1 > 0 (positive), so the graph of function opens upward and has a minimum value.

The minimum value (y - coordinate of the vertex) is - 9/4.

Step 3 :

Find the y -  intercept :

To find the y - intercept, Substitute the value x = 0 in the original function, f(x) = y = x2 - 7x + 10.

y = (0)2 - 7(0) + 10

y = 10.

The y - intercept is 10.

The point is (0, 10).

Find the x -  intercept :

To find the x - intercept, Substitute the value y = 0 in the original function, f(x) = y = x2 - 7x + 10.

x2 - 7x + 10 = 0

x2 - 5x - 2x + 10 = 0

x(x - 5) - 2(x - 5) = 0

(x - 2)(x - 5) = 0

The x - intercept is 2 and 5.

The points are (2, 0) and (5, 0).

Step 4 :

  • Since, The axis of symmetry divides the parabola into two equal parts.So, if there is a point (0, 10) on one side, there is a corresponding point on other side that is the same distance from the axis of symmetry and has the same y - value.
  • The distance between the points (0, 10) and (7/2, 10) = 3.5 = The distance between (7/2, - 9/4) and the point (x, 10) paired with it on other side of the axis of symmetry and has the same y - value.
  • The distance between (7/2, 10) and the point paired with it on other side of the axis of symmetry. = 7/2 + 3.5 = 7.
  • Therefore, The point paired with it on other side of the axis of symmetry is (7, 10).
  • Connect these points and create a smooth curve.

Graph :

The graph of function f(x)=x^2+6x-6

 

answered Oct 29, 2014 by casacop Expert

Related questions

asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Nov 6, 2014 in PRECALCULUS by anonymous
asked Nov 5, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Oct 29, 2014 in PRECALCULUS by anonymous
asked Nov 13, 2014 in CALCULUS by anonymous
asked Nov 12, 2014 in CALCULUS by anonymous
asked May 24, 2019 in CALCULUS by anonymous
...