Find all real values of m for which the inequalty mx2- 4x + 3m + 1 >0 is satisfied for all positive x.
piyush soni
11 Years agoGrade 11
1 Answer
Nishant Vora
11 Years ago
Hello Student, Please find the solution
The value of this quadratic is always positive (>0) So graph will always be above x-axis therefore the condition will be :- D>0 and a>0 (parabola upwards and not touching the x-axis)
Solve both the conditions nw 1) D>0 16 – 4m(3m+1) >0 16 – 12m2 – 4m >0 multiplying by -1 both side 12m2+ 4m -16<0 Divide by 4 3m2+m – 4 <0 3m2+4m – 3m – 4 <0 m(3m+4) – 1 (3m + 4) <0 (3m+4)(m – 1) <0