Salut,
(2t - 1)² <(-t + 1)(-2t + 1)
(2t-1)² - (-t+1)(-2t+1) < 0
(2t-1)(2t-1) - (-t+1)(-2t+1) < 0
(2t-1)[(2t-1) - (-t+1)] < 0
(2t-1)(2t-1 +t - 1) < 0
(2t-1)(3t -2) < 0
2t - 1 < 0
2t < 1
t < 1/2
3t - 2 < 0
3t < 2
t < 2/3
S = ]-infini; 1/2[
3/(2a) ≥ -4/(a-1)
[tex] \frac{3}{2a} \geq \frac{-4}{a-1}\\
\frac{3}{2a} - \frac{-4}{a-1} \geq 0\\
\frac{3(a-1)}{2a(a-1)} - \frac{-4(2a)}{2a(a-1)} \geq 0\\
\frac{3(a-1) - (-4(2a))}{2a(a-1)} \geq 0\\
\frac{3a - 3 + 8a}{2a(a-1)} \geq 0\\
\frac{11a - 3}{2a(a-1)} \geq 0[/tex]
11a - 3 ≥ 0
11a ≥ 3
a ≥ 3/11
et
2a(a-1) ≠ 0
2a ≠ 0
a ≠0
a - 1 ≠ 0
a ≠ 1
S = [3/11; 1[ U ]1; + infini[
Bonne soirée !
