This week in pre-calculus 11, we learned how to solve quadratic inequalities and graph them. This was a review from last year’s math.
y=mx+b is the equation used for linear graphs, which are graphs with straight lines that increase or decrease by the same number each time. b is the y-intercept, and m represents the slope of the graph.
A quadratic inequality is just like a quadratic equation, but instead of an equal sign, there’s an equality.
*always flip signs when dividing by a b=negative number
Solving the Inequality:
- Factor the inequality
- Find the Values of x
- select numbers in between the x values and test it in the inequality
Graphing
*the value of a in = a +b + c, can tell us if the graph opens up or down, which tells us the positive and negative values of the quadratic inequality when the it intercepts with x.
signs:
- ≥ greater than or equal to has a line, shaded dot
- ≤ less than or equal to has a line, shaded dot
- > greater than has a dotted line, unshaded dot
- <less than has a dotted line, unshaded dot