What is the exact value of
cos (-105)°

Could someone me with this question i’ve been stuck on it for 20 minutes

Your car's gasoline tank holds 18 gallons of gasoline. on a trip in canada, the tank is one-quarter full. you want to fill the tank. how many liters of gasoline are needed to fill the tank

Let f(x) = 1/x^2 (a) use the definition of the derivatve to find f'(x). (b) find the equation of the tangent line at x=2