Youssef H.

asked • 03/06/16

How would write this quadratic function in standard form?

intercepts are (-7,0) and (3/5,0) what really got me is that fraction. THANKS!

Michael J.

When you give 2 points, that is enough for only the equation of a line.  To get a quadratic function, you need at least 3 points.
Report

03/06/16

Vijay J.

yes right

Report

03/07/16

Michael J.

Usually, you would need at least 3 points to write the quadratic function.  However, you have two points of the same type.  Therefore, you can get the quadratic function using those points.  Thus, you see my solution below.
Report

03/07/16

1 Expert Answer

By:

Michael J. answered • 03/07/16

Tutor
5 (5)

Effective High School STEM Tutor & CUNY Math Peer Leader

See tutors like this
See tutors like this
Actually, you can get the quadratic function using two points.  Since your two points are x-intercepts, we can put these x-intercepts in factored form.  We know that an x-intercept is when  f(x)=0.  This means when x=-7 and x=3/5, the value of f(x) is zero.
 
The factor (x + 7) yields the x-intercept (-7, 0).  The factor (5x - 3) yields the x-intercept (3/5, 0).
 
f(x) = (x + 7)(5x - 3)
 
 
Expand this to get
 
f(x) = 5x2 + 32x - 21
Upvote • 0 Downvote
More
Report

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.