Cos(x+y)cos(x-y)=cos^2y - sin^2x

Consider the function y = f(x)=3^x the values of f(1/2) and f(1/4). rounded to the nearest hundredth, are__and__ respectively

Julius sold five times as many computers as sam sold last year. in total, they sold 78 computers. how many computers did julius sell?

Three baby penguins and their father were sitting on an iceberg 0.50.50, point, 5 meters above the surface of the water. the father dove down 4.74.74, point, 7 meters from the iceberg into the water to catch dinner for his kids. what is the father penguin's position relative to the surface of the water?