Question 972375
Find and simplify the difference quotient of (f(x+h) - f(x)) /h where f(x)=x^2+2x+3 and h can't = 0
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f(x)=x^2+2x+3
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f(x+h)=(x+h)^2+2(x+h)+3
f(x+h)=(x+h)(x+h)+2(x+h)+3
f(x+h)=x^2+2hx+h^2+2x+2h+3
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substitute the above into:
(f(x+h) - f(x)) /h
(x^2+2hx+h^2+2x+2h+3 - (x^2+2x+3)) /h
(x^2+2hx+h^2+2x+2h+3 -x^2-2x-3) /h
(2hx+h^2+2x+2h+3-2x-3) /h
(2hx+h^2+2h+3-3) /h
(2hx+h^2+2h) /h
2x+h+2  (answer)