I have some doubts in the answer of todays puzzle on 18/9/12. you are given there are two positive roots.But p(0) =4 and when you give any values > 0 for x there is no sign change.so intermediate value theorem there will be no roots. also I think that Descartes rule of sign doesn"t assure the roots. please clarify my doubts. I expect your valuable comments

• yes jomon... i agree with you... I also have the same doubt in mind... by sign changes we can determine the number of positive or negative roots and maximum number of real roots only... we cant say exact number of real roots in this way...
  I dont know how they determined it... lets ask it in discussion board... admin may clarify our doubt...
• 11 years agoHelpfull: Yes(1) No(1)