Search our library of GCSE questions

Top answers

All subjects

GCSE

A circle has equation x^{2}-8x+y^{2}-6y=d. A line is tangent to this circle and passes through points A and B, (0,17) and (17,0) respectively. Find the radius of the circle.

Gradient of line: (0-17)/(17-0)= -1 equation of line: y-y₁=m(x-x₁) y-17=-1(x-0) y=17-x equation of circle: (x-4)²+(y-3)²-25=d (completing the square) (x-4)^...

Answered by Amirali H. • Further Mathematics tutor

2461 Views

Conjugate the verb Jugar for each person in preterite form

JuguéJugasteJugóJugamosJugasteisJugaron

Answered by Armand D. • Spanish tutor

1422 Views

Explain how carbon monoxide is produced when petrol is burned in car engines. (2 marks)

Car petrol is usually some form of alkane, which has the general formula C_nH_2n+2. Let us assume we are using Butane (C₄H₁₀). The desired chemical reaction for t...

Answered by Luc B. • Chemistry tutor

13587 Views

A person swims from a depth of 0.50 m to a depth of 1.70 m below the surface of the sea. Density of the sea water = 1030 kg/m^3. Gravitational field strength = 9.8 N/kg. Calculate the increase in pressure on the swimmer. Give the unit.

We may use from the equation sheet, that p = h ρ g. Here, we are looking for a change in pressure, so one or more of the terms on the other side of the equation must be changing too. The question tells us...

Answered by Luc B. • Physics tutor

5073 Views

What is osmosis and how does it work?

Osmosis is defined as the movement of water from an area of high water potential to an area of lower water potential, across a partially permeable membrane. This means that water molecules moves from a ve...

Answered by Rebekah D. • Biology tutor

2832 Views