Higher Plus

A histogram has two bars: one 20 units wide with frequency density 2.5, one 20 units wide with density 0.6. How many values in total?

A rectangle is 16 cm by 8 cm, each correct to the nearest cm. Work out the upper bound of its area.

Write 3/(x + 3) + 3/(x + 6) as a single fraction.

y is directly proportional to x². When x = 5, y = 100. Work out the positive value of x when y = 144.y is directly proportional to x^2. When x = 5, y = 100. Work out the positive value of x when y = 144.

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.