Top answers

Find the equation of the straight line joining points (-1, -4) and (2, 5)

Draw sketch of line 2. Find gradient using m=(y 2 - y 1 )/(x 2 - x 1 )= 5--4/2--1=9-3=3 3. Choose one of the points and call it (a,b). I'll pick (2,5) because there's no negaitves. 4. Sub into equation y-b=m...
BM
Answered by Ben M. • Maths tutor
9044 Views

How is an action potential formed when the neurone is stimulated?

When the neurone is stimulated , the Na+ channels open to allow influx of sodium ions down its electrochemical gradient. This makes the inside of the cell less negative. When threshold voltage (-55mV) is rea...
IC
Answered by Ismael C. • Biology tutor
3330 Views

Solve, correct to 2 decimal places, the equation cot(2x)=3 for 0°<x<180°

To start, we use the inverse trigonometric formulae to convert the 'cot' function into a 'tan' function: cot(2x)=1/(tan(2x))=3 Inverting this gives: tan(2x)=1/3 2x=arctan(1/3)=18.43°or (180+18.43)° Therfore ...
MG
Answered by Matthew G. • Maths tutor
9904 Views

Solve x^2 = 4(x – 3)^2

Expanding and simplifying the right hand side: x 2 =4(x-3)(x-3)=4(x 2 -6x+9)=4x 2 -24x+36 Deducting 'x 2 ' from both sides: 0=3x 2 -24x+36 Dividing by 3 and factorising: 0=x 2 -8x+12=(x-6)(x-2) Therefore sol...
MG
Answered by Matthew G. • Maths tutor
3578 Views

Factorise the following expression: x^2+12x-45

x^2+12x-45 x^2+15x-3x-45 (15x - 3x= 12x and 15 x -3=-45) x(x+15)-3(x+15) (x-3)(x+15)
AH
Answered by Aisha H. • Maths tutor
4103 Views