Top answers

A circle with centre C has equation: x^2 + y^2 + 20x - 14 y + 49 = 0. Express the circle in the form (x-a)^2 +(y-b)^2=r^2. Show that the circle touches the y-axis and crosses the x-axis in two distinct points.

Firstly we rearrange the expression to the required form:x 2 + y 2 + 20x - 14y + 49 = 0 which gives (x + 10) 2 - 100 + (y - 7) 2 - 49 + 49 = 0 and so (x - (-10)) 2 + (y -7) 2 = 10 2 Hence a = -10, b = 7 and ...
JI
Answered by John I. • Maths tutor
7960 Views

Integrate ln(x/7) with respect to x

Firstly split up the ln(x/7) = ln(x) - ln(7) using rules of logarithms learnt in your first year of A-levels, as this will reduce any likely error.Secondly, recognise that the -ln(7) term is constant, and so...
AS
Answered by Arjun S. • Maths tutor
3782 Views

How can I prepare for an exam or essay that requires comparing two texts?

Firstly, you should check your syllabus to see what stipulations there are about the texts you are comparing. Does one have to be a poem, or pre-1900, do you have to compare two different mediums of texts su...
IM
4592 Views

A myelinated axon conducts impulses faster than a non-myelinated axon. Explain this difference:

A myelinated neurone is insulated by a layer of Schwann cells that make up the myelin sheath. This aids in the faster conduction of an action potential down the neuronal axon. Depolarisation of the axon can ...
HP
Answered by Hanna P. • Biology tutor
22971 Views

A force of 13.8 N was used to lift a mass 30 cm vertically through a liquid. Calculate the work done in lifting the mass, stating the correct units.

Either from memory or using the formula booklet provided we know Work Done = Force x Distance Moved (in the direction of the force). Therefore we can use the values given and this formula to workout our answ...
HG
Answered by Harry G. • Physics tutor
4698 Views