True or false ? euclidean geometry is based on the postulates of euclid

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Which sentence uses an objective tone? we will plant the best garden of any school in the area. the new campus garden will surely be envied by other schools. a garden would provide numerous benefits to the students. you will probably agree that gardens have many benefits.

Find the zeros of each function. f(x) = 6x^2 - 7x - 20