Read the proof. What is step 2?

sin(2x) = cos(x)cos(x) – sin(x)sin(x)
sin(2x) = sin(x)cos(x) – sin(x)cos(x)
sin(2x) = cos(x)cos(x) + sin(x)sin(x)
sin(2x) = sin(x)cos(x) + sin(x)cos(x)

Asap for seven months an ice creams vendor collects data showing the number of cones sold a day (c) and the degrees above 70 degrees f the vendor finds that there is a positive linear association between c and t that is the best modeled by this equation c=3.7t+98 which statement is true? the model predicts that the average number of cones sold in a day is 3.7 the model predicts that the average number of cones sold i a day is 98 a model predicts that for each additional degree that the high temperature is above 70 degres f the total of number of cones sold increases by 3.7 the model predicts for each additional degree that the high temperature is above 70 degrees f the total number of cones sold increasingly by 98

We just started the introduction into circles and i have no idea how to do this.

Rewrite the following quadratic functions in intercept or factored form. show your work. f(x) = 3x^2 - 12