If [tex]x[/tex] is real and p=[tex]\frac{3(x^{2} +1)}{2x-1}[/tex], prove that [tex]p^{2}[/tex]-3(p+3) ≥ 0

Respuesta :

Answer:

[tex]{ \tt{p=\frac{3(x^{2} +1)}{2x-1}}} \\ { \tt{p(2x - 1) = 3( {x}^{2} + 1) }} \\ { \tt{2px - p = 3 {x}^{2} + 3 }} \\ { \tt{3 {x}^{2} - (2p)x + (p + 3) = 0}} [/tex]

By factorization :

[tex]{ \tt{ ( {p}^{2} - 3)( p + 3) \: is \: the \: zero}}[/tex]

Since the roots are real, they're greater than zero ( 0 < x ≤ +∞ ):

[tex]{ \tt{ ({p}^{2} - 3})(p + 3) \geqslant 0}[/tex]