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Given that x(a+bx)(a-bx)=25x-4x^3, what is the value of b^(-a)? a,b>0

It's a two part question. First Part Expand the equation the left hand side to get a^(2)*x-b^(2)*x^3 thus comparing co-efficients a^2=25 and b^2=4 thus a= 5 b=2 Second Part Therefore b^(-a) is equal to 2^(-5...
CP
Answered by Cameron P. Maths tutor
10600 Views

Solve the inequality 7x+3y-4 > 5y-19x for y in terms of x.

7x+3y-4 > 5y-19x Adding 19x to both sides: 26x+3y-4 > 5y Subtracting 3y from both sides: 26x-4 > 2y Divide both sides by 2 to put the expression in its simplest form: 13x-2 > y or (remembering to...
DL
Answered by Danny L. Maths tutor
4308 Views

How would you derive y = function of x; for example: y = 3x^3 + x^2 + x

The best way to remember derivatives is to use algebra, and the general function is y = ax n -> dy/dx = anx n-1 So for this equation dy/dx = (3x3)x 3-1 + (2x1)x 2-1 + 1x 1-1 So the answer would be dy/dx =...
GA
Answered by George A. Maths tutor
3631 Views

How do you solve quadratic inequalities?

Quadratic inequalities generally don't arrive in the standard quadratic form (Ax^2 + Bx +c) and so can be sometimes difficult to spot. However, if you see an X^2 - or brackets that expand to X^2 - on either ...
DK
Answered by David K. Maths tutor
3624 Views

Factorise and solve x2 - 8x + 15 = 0

Factorise the quadratic into two brackets to make (x-3)(x-5)=0 Because the product of these brackets is zero then the value of one of the brackets must equal zero. In order for one of the brackets to have a ...
MS
Answered by Mohamed S. Maths tutor
9338 Views