Question

What is the derivative of z=3x*logx+5x^6 with respect to x?

(a) 3+30x^5 e^x

(b) 3+5x^6 e^x+30x^5 e^x

(c) 3+5x^6 e^x

(d) 3+3logx+30x^5 e^x

This question was posed to me in an interview.

My enquiry is from Geometrical Applications topic in section Ordinary Differential Equations – First Order & First Degree of Engineering Mathematics

Answer 1

Correct option is (d) 3+3logx+30x^5 e^x

To explain: Given: z = 3x*logx+5x^6 e^x

\(\frac{dz}{dx}=3x(\frac{1}{x})\)+3logx+30x^5 e^x

\(\frac{dz}{dx}\) = 3+3logx+30x^5 e^x