# Differentiate

1. Consider the function f(x)=(−5x^(2))+7x+15.

a) For the given function f, the expression f(x+h)-f(x)/h can be simplified to the form Ax+Bh+C, where A, B and C are constants. Do it.

Answer: f(x)=(−5x^2)+7x+15=____x+____h+____

b) Using the result of (a), find the derivative of f at x .

Answer: f'(x)=______. Note. The correct answer should be an expression in x.

c) Suppose that the position of a particle at time t is given by s=−5t^(2)+7t+15. What is the particle's instantaneous velocity at time t=2?

Answer: The particle's instantaneous velocity at time t=2 is _____

2. Differentiate the given functions. For this question, you may use the following differentiation rules and formulas:

If r is any rational number, then d/dx (x^r)=rx^(r-1).

If f and g are differentiable functions of x, and if α and β are constants, then

d/dx (αf(x)+βg(x))= α d/dx (f(x))+β d/dx (g(x)).

In each case, state the domain of the derivative.

a) f(x)=−3x^(3)−1x^(2)−4x+1.

Answer: The derivative of f(x) is f'(x)=______, and the domain of f' is ______

b)f(x)=5x^(3/2)-2x^(1/2)-1x^(-1/2)-4x^(-3/2).

Answer: The derivative of f(x) is f'(x)=_____, and the domain of f' is _____

c) f(x)=-3sqrt(x)+2/sqrt(x)+2/x+_3/x^(2).

Answer: The derivative of f(x) is f'(x)=______, and the domain of f' is ______

3. Differentiate the following functions and simplify your answers into the specified form.

a) f(x)=-1x-7/-10x^(2)-7.

Answer: f'(x)=1/(-10x^(2)-7)^2 (____x^(2)+_____x+____)

b) g(x)=x^(3)/-9x+6

Answer g'(x)= 1/(-9x+6)^2 (____x^(3)+_____x^(2)+_____x+_____)

4. Differentiate the following functions and simplify your answers into the specified form.

a) f(x)=(12x−8)sinx+(−7x−5)cosx.

Answer: f'(x)=(_____x+_____)sinx+(_____x+_____)cosx. Note: The four answers should be constants

b) g(x)=(5x^(2)−8)tanx.

Answer: g'(x)=(_________)sec^(2)x+(___________)tanx. Note: The two answers shoud be functions of x

#### Solution Preview

Hi,

Please find the solutions/explanations attached herewith.

1. Consider the function f(x) = (−5x^(2))+7x+15.

a) For the given function f, the expression f(x+h)-f(x)/h can be simplified to the form Ax+Bh+C, where A, B and C are constants. Do it.

f(x+h) = -5(x+h)^2 + 7(x+h) + 15

f(x) = -5x^2 + 7x + 15

Answer: -10x - 5h + 7

Answer: f(x)=(−5x^2)+7x+15= -10x+(-5)h+7

b) Using the result of (a), find the derivative of f at x .

Answer: f'(x)=______. Note. The correct answer should be an expression in x.

Put h = 0

f'(x) = -10x + 7

c) Suppose that the position of a particle at time t is given by ...

#### Solution Summary

The expert differentiates the given functions. Simplified expressions for functions are determined.