Question 1160584
(a). y = x(x-3)(x+4)
<pre>
Use formula
     y = product of the 1st and 2nd times the derivative of the 3rd
             plus
         product of the 1st and 3rd times the derivative of the 2nd
             plus   
         product of the 2nd and 3rd times the derivative of the 1st
             
{{{dy/dx=x(x-3)(1)+x(x+4)(1)+(x-3)(x+4)(1)}}}
{{{dy/dx=x(x-3)+x(x+4)+(x-3)(x+4)}}}
{{{dy/dx=(x^2-3x)+(x^2+4x)+(x^2+x-12)}}}
{{{dy/dx=x^2-3x+x^2+4x+x^2+x-12}}}
{{{dy/dx=x^2+x^2+x^2-3x+4x+x-12}}}
{{{dy/dx=3x^2+2x-12}}} 

Or multiply it out first

{{{ y = x(x-3)(x+4)}}}
{{{y=(x^2-3x)(x+4)}}}
{{{y=x^3+4x^2-3x^2-12x}}}
{{{y=x^3+x^2-12x}}}
{{{dy/dx=3x^2+2x-12}}}

Same answer
</pre>
(b). y= 7x+17x^2+30x^3</pre>
{{{y= 7x+17x^2+30x^3}}}
{{{dy/dx=7+34x+90x^2}}}</pre>
(c). y= 5e^x+9inX-x^9+8<pre>

That makes no sense. Sorry!

Edwin</pre>