Thursday, February 18, 2010

post 26

here we go

First Derivative Test:

1. Take the derivative of the original problem.
2. Set the first derivative equal to Zero.
3. Solve for x.
4. Create intervals for x. i.e. (-∞, 1) (1, 4) (4, ∞)
5. Pick a number in the intervals then plug that number in the first derivative for x.
6. Solve. For positive numbers, the graph of the derivative is above the x-axis. For negative numbers, the graph of the derivative is below the x-axis. The numbers for x are your points of inflection. (Points of Inflection are only if there is a shift in the graph!!!)

Second Derivative Test:

1. Take the derivative of the first derivative.
2. Set the second derivative equal to Zero.
3. Solve for x.
4. Create intervals for x. i.e. (-∞, 1) (1, 4) (4, ∞)
5. Pick a number in the intervals then plug that number in the second derivative for x.
6. Solve. For positive numbers, the graph of the derivative is above the x-axis. For negative numbers, the graph of the derivative is below the x-axis. The numbers for x are your points of inflection. (Points of Inflection are only if there is a shift in the graph)

RELATED RATES:
1. identify all variables and equations
2. identify what you are looking for
3. sketch and label
4. write an equations involving your variables (you can only have one unknown so a secondary equation may be given)
5. take the derivative (with respect to time)
6. substitute in derivative and solve

Tangent line- they give you a function and an x value. If no y value is given, plug the x value into the original function. To find the slope, you take the derivative of the original function and plug the x value in. Then you set it up into point slope form. y-y1= slope(x-x1). For a normal line, you would take the negative inverse of the slope and solve.

im need help w/ e-integration, tangent lines i can never remember, and thats bout it.

2 comments:

  1. Equation of a tangent line:
    Take the derivative and plug in the x value.
    If you are not given a y value, plug into the original equation to get the y value.
    then plug those numbers into point slope form: y − y1 = m(x − x1)

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