Top answers


Solve algebraically the simultaneous equations x^2 + y^2 = 25 y – 3x = 13

First begin with rearranging the second equation to put it in terms of Y. Then substitute by putting the second equation (y=3x+13) into equation one as Y^2. Expand (3x+13)^2 and add like terms to form 10x^2 ...
DL
Answered by Dani L. Maths tutor
3545 Views

y = x^2 + 3x + 2 = 0

Factorising gives: y = (x+2)(x+1) = 0. y only equals 0 when (x+2)=0 or (x+1)=0. Therefore x=-2 or x=-1
DT
Answered by Dr Thomas P. Maths tutor
3016 Views

Find the integers n such that 4^(n)-1 is prime.

4^(n)-1 factors to (2^(n)-1)(2^(n)+1) by difference of two squares by definition of a prime (only has factors 1 and itself (given that itself isn't 1))So Exactly one of the brackets should = 1 for 4^(n)-1 to...
GH
Answered by George H. Maths tutor
3438 Views

Given that y = x^2 +2x + 3, find dy/dx.

We use a typical rule for polynomials in the form y = a x b , where a and b are real numbers. Also, for a polynomial equation y = a x b +c x d +.... , dy/dx = d( a x b )/dx + d(c x d )/dx + ...With this info...
JC
Answered by Jamie C. Maths tutor
6238 Views

How to differentiate e^x . sin(x)

e x sin(x) is a product of two functions: e x and sin(x). This means we can use the product rule. Let e x = u and sin(x) = v The differential of uv is u'v + v'u where u' and v' are the two functions differen...
BW
Answered by Brent W. Maths tutor
45221 Views