+0  
 
0
126
1
avatar

Find the product of all positive integer values of c such that  \(8x^2+15x+c=0\) has two real roots.

Guest Jan 1, 2018
Sort: 

1+0 Answers

 #1
avatar+86649 
+1

8x^2  +  15x   + c  =   0

 

This will nave two real  roots if

 

15^2  -  4 * 8 * c  >  0

 

225  -  32c  >  0

 

225  >  32c

 

225/ 32  > c

 

7.03125  > c

 

So......c will have two real roots  [and  be positive ]   for  all  integer values  from 1 to 7, inclusive

 

And the procuct of these possible values for c   =  7!   =  5040

 

 

 

cool cool cool

CPhill  Jan 2, 2018

7 Online Users

avatar

New Privacy Policy (May 2018)

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. Please click on "Accept cookies" if you agree to the setting of cookies. Cookies that do not require consent remain unaffected by this, see cookie policy and privacy policy.