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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
9037 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
9895 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
3573 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
4092 Views

How do I factorise this expression? [Let’s say it’s x^2 + 5x + 6]

The expression is of the form ax^2 + bx + c. Here, a = 1 and this makes it easier for us. We can also see that b = 5 and c = 6. In general, we have to find two numbers that multiply to get c and add to get b...
LC
Answered by Luke C. • Maths tutor
4005 Views