Let f be the function f(x) = 4 For what positive value of x is the gradient of the tangent to the graph of f at (x, f(x)) equal to 4?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

The graph represents the gallons of water in a water tank with respect to the number of hours since it was completely filled