Limits and Derivatives

[jay2012]

JUST WANT TO GET ASSURED WITH THE ANSWERS:
how to find the derivatives;

a) f(x) = 6x^2 + (2/x^3) + 5pi
b) f(x) = (1+ 2sinx) / cox
c) f(x) = x(3sinx+2cosx)
d) f(x) = (tanx - 8) / secx
e) f(x) = 2sinx + cosx [determine f^(2) (x)]

answers (?):

a) f'(x) = 3[(2x^4+1)/x3]
b) f'(x) = (2-cox)/sin^2x
c) f'(x) = (3-2x)sinx + (3x+2)cosx
d) f'(x) = cosx + 8sinx OR f'(x) = cosx - 8sinx
e) f'^(2)(x) = sinx + 2 cos x


AND

Derivatives:

a) finding the x-int of the tangent line to the graph of f(x)=3+2x+4x^2-4x^4 at P= (-1, f(-1))

b) determining if the lim x>0 (sin5x)/6x exists 'n finding the value
c) determining if the lim x>0 (sin3x)/sin5x exists 'n finding the value

d) finding the value of F'(6) when F'(x) = f(x)/f(x)-g(x) and f(6) = 4, f'(6) = 1, g(6) = 1, g'(6) = 5

Answers (?);

a) x-int = 3/2
b) limit = 5
c) limit = 5/3
d) F'(6) = 7/3

if you get another answer just write it down so I can match and see where I've made the mistakes. You don't have to write the methods.

Thanks

 

[Deleted member 4993]

JUST WANT TO GET ASSURED WITH THE ANSWERS:
how to find the derivatives;

a) f(x) = 6x^2 + (2/x^3) + 5pi
b) f(x) = (1+ 2sinx) / cox
c) f(x) = x(3sinx+2cosx)
d) f(x) = (tanx - 8) / secx
e) f(x) = 2sinx + cosx [determine f^(2) (x)]

answers (?):

a) f'(x) = 3[(2x^4+1)/x3] ..........................................Incorrect
b) f'(x) = (2-cox)/sin^2x ..........................................Incorrect
c) f'(x) = (3-2x)sinx + (3x+2)cosx
d) f'(x) = cosx + 8sinx OR f'(x) = cosx - 8sinx
e) f'^(2)(x) = sinx + 2 cos x


AND

Derivatives:

a) finding the x-int of the tangent line to the graph of f(x)=3+2x+4x^2-4x^4 at P= (-1, f(-1))

b) determining if the lim x>0 (sin5x)/6x exists 'n finding the value
c) determining if the lim x>0 (sin3x)/sin5x exists 'n finding the value

d) finding the value of F'(6) when F'(x) = f(x)/f(x)-g(x) and f(6) = 4, f'(6) = 1, g(6) = 1, g'(6) = 5

Answers (?);

a) x-int = 3/2
b) limit = 5
c) limit = 5/3
d) F'(6) = 7/3

if you get another answer just write it down so I can match and see where I've made the mistakes. You don't have to write the methods.

Thanks

I did not check the rest.

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