Posted by **Jayson** on Monday, December 19, 2011 at 2:39pm.

Help appreciated~

1.Use the quadratic formula to determine when f(x)= x^2 +7x + 7 is greater than 0. Round your answer to two decimal places.

a) x<-5.79, x>-1.21

b) x<-7, x>1

c) 1<x<7

d) -5.79<x<-1.21

----------------------------------------

2. On what interval will the function f(x) = x^2 - 5x -6 have a positive rate of change?

a) -1<x<6

b) x>2.5

c) x<-1, x>6

d) x is less than or equal to 2.5

- precalculus -
**Steve**, Monday, December 19, 2011 at 3:11pm
1.

find the roots of the function: (-7 +/- sqrt(21))/2 = -5.79 and -1.21

Since the graph is a parabola which opens up, it will lie below the x-axis between the roots, and above the axis elsewhere.

A is the answer

2.

Again, you have a parabola which opens up. If you can find the vertex, f(x) will be decreasing on the left, and increasing on the right of the vertex.

The vertex, natch, is at x = -b/2a = 5/2.

So, B is the answer

## Answer this Question

## Related Questions

- math - round result to two decimal places...the answer i have is: 7.023 so two ...
- college stats - Again sorry for all the questions. please help, I am not good at...
- Chemistry - 1. Calculate the pH of a buffer solution that contains 0.32 M ...
- Chemistry - 1. Calculate the pH of a buffer solution that contains 0.32 M ...
- Calculus - Consider the function below. f(x) = [1-(4/x)]^x (a) Use a graph to ...
- Pre Calc - Use the doubling time to find the continuous percent growth rate and ...
- precalculus - Determine the x-intercepts of the polynomial function y=-6(x+7)^4...
- 5 Pre-Calculus Questions - 1. What is the value of x in the right triangle below...
- statistics check - Consider the following bivariate data. Point A B C D E F G H ...
- math - i have no clue how to do this problem. any help would be appreciated...