Question

oi complete a tabela e esboce o grafico da função pfvrr​

Answer 1

$\boxed{\begin{array}{c|c|c}\sf A&\sf2\alpha&\sf f(\alpha)=cos(2\alpha)\\\sf0&\sf2\cdot0&\sf1\\\sf\dfrac{\pi}{4}&\sf2\cdot\dfrac{\pi}{4}&\sf0\\\sf\dfrac{\pi}{2}&\sf2\cdot\dfrac{\pi}{2}&\sf-1\\\sf\dfrac{3\pi}{4}&\sf2\cdot\dfrac{3\pi}{4}&\sf0\\\sf\pi&\sf2\cdot\pi&\sf1\\\sf\dfrac{5\pi}{4}&\sf2\cdot\dfrac{5\pi}{4}&\sf0\\\sf\dfrac{3\pi}{2}&\sf2\cdot\dfrac{3\pi}{2}&\sf-1\\\sf\dfrac{7\pi}{4}&\sf2\cdot\dfrac{7\pi}{4}&\sf0\\\sf2\pi&\sf2\cdot2\pi&\sf1\end{array}}$