Prove the property: log_a(x) + log_a(y) = log_a(xy).

The derivation of the property starts with the basic representation of logarithms as powers. Lets consider a^(log_a(xy)). Then, a^(log_a(xy)) = xy. However, x = a^(log_a(x)) and y = a^(log_a(y)). Therefore, xy = a^(log_a(y)) * a^(log_a(x)) = a^(log_a(x) + log_a(y)). Hence, log_a(x) + log_a(y) = log_a(xy).

Related Maths A Level answers

All answers ▸

The curve C has equation y=2x^2 -11x +13. (a) The point P has coordinates (2, – 1) and lies on C. Find the equation of the tangent to C at P.


What is the point of a derivative?


Find an expression in terms of powers of cos(x) for cos(5x)


Find the minimum and maximum points of the graph y = x^3 - 4x^2 + 4x +3 in the range 0<=x <= 5.