Posting...#31

Don't forget about your tangent line andd your normal line.

Tangent Line:

1. If you are only given a x value, plug into your equation to find the y value.

2. take the derivative of the equation

3. Plug in your x value into the derivative to find the slope

4. Put in point slope

EXAMPLE: y=3x^3 + 4x^2 +5 at x=1

1. 3(1)^3+4(1)^2+5 = 12

2. 9x^2 + 8x

3. 9(1)^2 + 8(1) = 17

4. y-12 = 17 (x-1)

Normal line is the same except you take the negative reciprocal of the slope to plug in.

y-12 = -1/17 (x-1)

And also your disk.

FORMULA FOR DISKS: pi S[r(x)]^2dx, this formula is almost exactly the same as when you are asked to find the area of a disk, however, while finding the area you do not square the radius (the given equation).

FORMULA FOR WASHERS: pi S[(top)^2-(bottom)^2]dx

On the AP test lately i been missing the trapezoid questions which i thought i new so if someone could help me with taht thanks.