Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 11: Giúp em với ạ cos(2x/3 – π/3)=0

Toán Lớp 11: Giúp em với ạ
cos(2x/3 – π/3)=0

Comments ( 2 )

  1. Giải đáp: x=\frac{5π}{4}+\frac{k3π}{2} \ (k∈\mathbb{Z})
    Giải:
    cos(\frac{2x}{3}-\frac{π}{3})=0
    ⇔ \frac{2x}{3}-\frac{π}{3}=\frac{π}{2}+kπ
    ⇔ \frac{2x}{3}=\frac{π}{3}+\frac{π}{2}+kπ
    ⇔ \frac{2x}{3}=\frac{5π}{6}+kπ
    ⇔ 2x=\frac{5π}{2}+k3π
    ⇔ x=\frac{5π}{4}+\frac{k3π}{2} \ (k∈\mathbb{Z})
    Vậy x=\frac{5π}{4}+\frac{k3π}{2} \ (k∈\mathbb{Z})

  2. $cos\bigg(\dfrac{2x}{3}-\dfrac{\pi}{3}\bigg)=0$
    $⇔\dfrac{2x}{3}-\dfrac{\pi}{3}=\dfrac{\pi}{2}+k\pi$
    $⇔\dfrac{2x}{3}=\dfrac{5\pi}{6}+k\pi$
    $⇔x=\dfrac{5\pi}{4}+\dfrac{k3\pi}{2}(k∈Z)$
     

Leave a reply

222-9+11+12:2*14+14 = ? ( )