Please help with these:

1. The point P (4, -2) lies on the curve y = x²- 7x + 10. The point Q (x, x²- 7x + 10) is also on the curve. A student made the following observations. Which of the following is false.

a. The slope of the secant line PQ is equal to x-3 as long as x is not equal to 3.

b. The slope of the tangent line at P is 1.

c. The equation of the tangent line at P is x - y - 6 = 0.

2. Find the limit to the following sequence: 1, 9 1/2, 9 1/4, 9 1/8, 9 1/16...

3. Find the limit of the infinite sequence 16, -8, 4, -2, 1, -1/2...

4. Find the limit of the infinite sequence 7/3, 7/9, 7/27...