Higher Plus

The point (12, 16) lies on the circle x² + y² = 400. Work out the gradient of the tangent to the circle at that point.The point (12, 16) lies on the circle x^2 + y^2 = 400. Work out the gradient of the tangent to the circle at that point.

A bag holds 6 red, 4 blue and 2 green counters. Two are taken without replacement. Given neither is green, what is the probability both are red?

A histogram has two bars: one 20 units wide with frequency density 1.5, one 10 units wide with density 0.8. How many values in total?

A block has mass 790 g (to the nearest 10 g) and volume 10 cm³ (to the nearest cm³). Work out the upper bound of its density, to 2 decimal places.A block has mass 790 g (to the nearest 10 g) and volume 10 cm^3 (to the nearest cm^3). Work out the upper bound of its density, to 2 decimal places.

Solve 12x² - 5x - 25 = 0.Solve 12x^2 - 5x - 25 = 0.