I have attached a scan because I don't know what the first line has to do with the rest. Has the printed a mistake?

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- February 13th 2010, 07:44 AMStuck Manchain rule again
I have attached a scan because I don't know what the first line has to do with the rest. Has the printed a mistake?

- February 13th 2010, 08:03 AMCalculus26
Good eye -- for f(x) = x^(2x) you can not use the power rule as suggested by what follows

Power rule d (u^n)/dx = nu^(n-1)du/dx if n is a real number

however for x^(2x)

write y = x^(2x)

lny = 2xln(x)

y '/ y = 2ln(x) + 2

y ' = x^(2x)[2ln(x) + 2] but most certainly is not 2x*x^(2x-1)