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if x^2 + 9x + 20 = 0, what are the possible values of x?

So x 2 + 9x + 20 = 0 My preffered way of solving this equation is to factorise the equation. (Though I understand that different students may find other ways easier) Factorisation is where the above equation...
TP
Answered by Tilly P. • Maths tutor
11620 Views

How do I find the equation of a straight line?

Let's draw a line. It crosses the point (0,1), intercepting the y-axis (remember, y to the sky!) at 1 and the x-axis at the point (-2,0). An equation tells us what a line looks like, it's a way of describing...
DG
Answered by Dominique G. • Maths tutor
6889 Views

Given that d/dx(cosx)=-sinx show that d/dx(secx)=secx(tanx)

let y=sec(x) = 1/(cos(X)) = cos(x) -1 Thus dy/dx = -1(cos(x)) -2 (-sinx) = sin(x)/(cos(x)) 2 = 1/cos(x) x sin(x)/cos(x) =sec(x)tan(x)
OD
Answered by Owain D. • Maths tutor
13569 Views

x = 0.045 (45 recurring). Prove algebraically that x can be written as 1/22

x=0.045 (45 recurring) 10x = 0.45 (45 recurring) 100x = 4.54 (54 recurring) 1000x = 45.45 (45 recurring) To get rid of the decimals: 1000x-10x = 45.45 - 0.45 990x = 45 x = 45/990 x = 9/198 (simplify by divid...
JT
Answered by John T. • Maths tutor
60617 Views

How do I work out the area of a right angled triangle?

If we think about a right angled triangle, it is the same as one half of a square or rectangle. This is because if we join two right angled triangles at their diagonal sides, we make a square or rectangle. N...
CC
Answered by Ciaran C. • Maths tutor
20547 Views