Solve the trigonometry equation cos4x+cos2x

With this question! what is process of elimination? ? p.s. my brothers acc got banned so add his new one @ yamauchiyamyam17

The frequency table shows a set of data collected by a doctor for adult patients who were diagnosed with a strain of influenza. patients with influenza age range number of sick patients 25 to 29 30 to 34 35 to 39 40 to 45 which dot plot could represent the same data as the frequency table? patients with flu

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)