Derivative of (2x^2 + 1)x^(1/2) using Product Rule | Homework Question

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Homework Statement


Find the derivative of y= (2x2 + 1) x1/2


Homework Equations


Product Rule

The Attempt at a Solution


After differentiating, I eventually get stuck at:
\frac{4x<sup>3/2</sup>+2x<sup>2</sup>+1}{2\sqrt{x}}

The given solution is \frac{10x<sup>2</sup>+1}{2\sqrt{x}}
 
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the problem is in your algebra, on the left you have, after differentiating, (x^1/2)4x, now when putting it over a common denom, you get 2x^1/2[(x^1/2)4x] which becomes 2x times 4x... from here i think u can finish it correctly
edit: or the way you've done it, (4x^3/2) which is the left, you need to times it by the common denom, so 4x^3/2 times 2x^1/2
 
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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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