Hey I'm stuck on a problem, i have to find the differential of y=5x(2x-1)^3 and therefore find the x-coordinate of a stationary point on a graph,(adsbygoogle = window.adsbygoogle || []).push({});

I use the chain rule and get the differential to be 30x(2x-1)^2 and therefore the x-coordinate to be 0.5

however my textbook says the differential is 5(2x-1)^2(8x-1) and the x-coordinate of the stationary point is 1/8th I was wondering if someone could explain how this answer was obtained. Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Differentiation problem

**Physics Forums | Science Articles, Homework Help, Discussion**