Higher Plus

A histogram has two bars: one 5 units wide with frequency density 2, one 20 units wide with density 3. How many values in total?

A car covers 140 m (to the nearest 10 m) in 9 s (to the nearest second). Work out the lower bound of its speed, to 2 decimal places.

f(x) = 2x + 4. Work out the inverse function f^-1(x).f(x) = 2x + 4. Work out the inverse function f^-1(x).

y is directly proportional to x². When x = 5, y = 225. Work out the positive value of x when y = 441.y is directly proportional to x^2. When x = 5, y = 225. Work out the positive value of x when y = 441.

The point (9, 40) lies on the circle x² + y² = 1681. Work out the gradient of the tangent to the circle at that point.The point (9, 40) lies on the circle x^2 + y^2 = 1681. Work out the gradient of the tangent to the circle at that point.