Graph the function f(x)=\displaystyle {f{{\left({x}\right)}}}=x2+4x\displaystyle {x}^{{2}}+{4}{x} and draw the tangent lines to the graph at points whose x-coordinates are -2 , 0, and 1.
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Clear All Draw: LineParabola


Find the difference quotient f(x+h)f(x)h\displaystyle {\frac{{{f{{\left({x}+{h}\right)}}}-{f{{\left({x}\right)}}}}}{{{h}}}}  

Find f(x)\displaystyle {f}'{\left({x}\right)} by determining limh0f(x+h)f(x)h\displaystyle \lim_{{{h}\rightarrow{0}}}{\frac{{{f{{\left({x}+{h}\right)}}}-{f{{\left({x}\right)}}}}}{{{h}}}}.  

Find f(2)\displaystyle {f}'{\left(-{2}\right)} (This slope should match the tangent line you drew above.)
 

Find f(0)\displaystyle {f}'{\left({0}\right)}  

Find f(1)\displaystyle {f}'{\left({1}\right)}