Salut,
[tex]\left(tg\left(\dfrac{x}2\right)\right )'=\dfrac{1}{cos^2\left(\dfrac{x}2\right)}\cdot\left(\dfrac{x}2\right)'=\dfrac{1}{cos^2\left(\dfrac{x}2\right)}\cdot\dfrac{1}2=\dfrac{1}{2\cdot cos^2\left(\dfrac{x}2\right)}.[/tex]
Ai înțeles rezolvarea ?
Green eyes.
