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0O AT&T; LTE 9:18 PM math.mc.edu 16% 3.1 The Derivative and Problem 1 Previous P

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Question

0O AT&T; LTE 9:18 PM math.mc.edu 16% 3.1 The Derivative and Problem 1 Previous Problem List Next (1 point) Use the definition of the derivative (don't be tempted to take shortcuts!) to find the derivative of the function f(x) = 3x-7. f (z)- Preview My Answers Submit Answers You have attempted this problem 0 times. You have unlimited attempts remaining. Email instructor Page generated at 02/18/2016 at 09:18pm CST WeBWorK © 1996-2015 l theme: math4] ww-version: 2.101 pg version: 2.10 The WeBWorK Project

Explanation / Answer

1) f(x)=3x-7

f(x+h)=3(x+h)-7 =3x+3h-7

f '(x) =limh->0[f(x+h) -f(x)]/h

f '(x) =limh->0[3x+3h-7 -3x+7]/h

f '(x) =limh->0[3h]/h

f '(x) =limh->03

f '(x) =3

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2)f(x)=4x3-70x+8

f(x+h)=4(x+h)3-70(x+h)+8

f '(x) =limh->0[f(x+h) -f(x)]/h

f '(x) =limh->0[4(x+h)3-70(x+h)+8 -4x3+70x-8]/h

f '(x) =limh->0[4((x+h)3 -x3)-70h ]/h

f '(x) =limh->0[4((x+h-x)((x+h)2+(x+h)x +x2) -70h ]/h

f '(x) =limh->0[4(h)((x+h)2+(x+h)x +x2)  -70h ]/h

f '(x) =limh->0[4((x+h)2+(x+h)x +x2)  -70]

f '(x) =[4((x+0)2+(x+0)x +x2)  -70]

f '(x) =[4(3x2)  -70]

f '(x) =12x2 -70