Find the derivative of f(x) = 12x^2 + 8x at x = 9

find the derivative of f(x) = 4x + 7 at x = 5

find the derivative of f(x) = (1/7) at x = 1

find the derivative of f(x) = (-11/x) at x = 9

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

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?

Find the value of p for which the polynomial 3x^3 -x^2 + px +1 is exactly divisible by x-1, hence factorise the polynomial