Let y = x^x. Find dy/dx.

This question is suited to A2 maths students, particularly those who are doing further maths and may be looking for a challenge. In one question it tests the students ability to use implicit differentiation, the chain rule, the product rule, and log laws.Solution:We cannot simply multiply by the power and reduce it by 1 since our exponent is not a constant. We can take the natural logarithm of both sides, yielding log(y) = x log(x). We can then use implicit differentiation on the LHS and the product rule on the RHS to get (1/y) * dy/dx = log(x) + 1. We can then multiply through by y = xx to get our final form of dy/dx = xx(log(x) + 1). During a session these steps would be much more filled out - this is far easier to do with access to a whiteboard.

JG

Related Maths A Level answers

All answers ▸

5Sin[x]-4=2Cos[2x]


Find minimum and maximum of x^2+1 if they exist


2 equations intersect each other, y = x + 2 and y = x^2. Find the area of the shaded region between the points of intersection giving your answer to 3 significant figures. (shaded region will be shown)


Given y=2x(x^2-1)^5, show that dy/dx = g(x)(x^2-1)^4 where g(x) is a function to be determined.