PLS HELP ASAP! WILL GIVE BRAINLIEST

Anyone know? is appreciated! will mark brainliest if correct!

Kapil needed to buy a long wooden beam. he went to two sawmills that each charge an initial fee plus an additional fee for each meter of wood. the following equation gives the price (in dollars) of a wooden beam from the first sawmill as a function of its length (in meters). p = 5+20xp=5+20x

Cos^2x+cos^2(120°+x)+cos^2(120°-x)i need this asap. pls me