Derive the following with respect to x1: y=(x1*x2)/(x1+x2).

y is a function of x1 and x2. We are asked to derive y with respect to x1, meaning that x2 remains constant. 

Note that y' is the derivative of y.

Both the numerator and denominator of the fraction contain x1. Therefore, we will need to follow the quotient rule of differentiation.

dy/dx1=[ (x1*x2)' *(x1+x2) - (x1x2)(x1+x2)' ] / [(x1+x2)2] ,   

dy/dx1=[x2*(x1+x2)-(x1*x2*1)]/  [(x1+x2)2],

Therefore: dy/dx1=x2/(x1+x2)  -  x1*x2/(x1+x2)2

TK

Related Maths A Level answers

All answers ▸

It is given f(x)=(19x-2)/((5-x)(1+6x)) can be expressed A/(5-x)+B/(1+6x) where A and B are integers. i) Find A and B ii) Show the integral of this from 0 to 4 = Kln5


Differentiate f(x) = (3x + 5)(4x - 7)


how do integrate an equation with a surd or a fraction?


Differentiate y=x/sin(x)