# Pre-cal week 18

through out this past semester of pre calc 11 I’ve learned a lot of new ways of math, the one I would like to show you that has now stuck with me is how to determine non-permissible values from rational expressions. In this question, you first start by taking out the denominator. With this denominator factor it to find the x values. The denominator can never equal zero. By finding finding the x’s you are finding the non-permissible values.

# Pre- cal Week 17

One thing I learned this week in Pre Calc 11 is how to find the side of a triangle using Cosine Law. The Cosine Law is used when you need to find a third side of a triangle. Tip: When trying to find a third angle of a triangle use the Alternate Cosine Law.

A trick to knowing when you are going to be using the Cosine Law is when you see a question asking to find the measurement of the third side of the triangle, and they give you the other two sides of the triangle and the angle between them.

Below is an example of a triangle where you need to find the third side. I will show how I determine what formula to use and how to solve… # Pre-Cal, Week 13

I learned this week in Pre Calc 11 is how to write absolute value functions in piecewise notation. We already have learned about absolute values (reference back to week 3 blog post for reminder). This week we learned about piecewise notation, and how to understand and write it for a absolute value function.

Piecewise notation is used to describe a function that has different definitions for different parts of the graph. When writing absolute values we use piecewise notation to describe the absolute value of the number.

In the example below follow the steps I take to write a absolute value function in piecewise notation… # Pre – Cal week 12

II learned this week in Pre Calc is how to solve systems of equations using substitution. A way to solve a linear system is to use the substitution method. You use the substitution method by substituting one y-value in a equation with the other. While using the substitution method you first substitute y in the second equation with thefirst equation since y = y. After substituting y into the equation and solving for x the value of x can then be used to find y by substituting the number you found, with x. While using the substitution method you can also start by substituting x in the second equation with the first equation.

Below is a example of how I solved a systems of equations using the steps above… # Pre- Cal, Week 11

I This week in Pre- Cal 11, I learned this week how to graph linear equations in two variables. A linear equation divides a graph into two sections. A linear equation has variables to the first degree only! A linear inequality looks very similar to a linear equation, the difference between the two is that a linear equation has a “equals” symbol and a linear inequality has a “inequality” symbol. When writing or understanding a graph of a linear inequality we shade one side of two sections divided by the linear equation. The side of the linear equation that is shaded is the region that will “satisfy” the inequality.

To find the region that will satisfy the inequality we choose a point (called the test point) on either side of the slope and plug it into the linear inequality. Then solve the linear inequality. If the inequality sign is true to the numbers then shade in the region, if not shade in the opposite region on the graph. never choice a point in the graph .

Below is a example of how I graphed a linear equation in two variables using the steps above… # Pre- cal, Week 10

This week in Pre- Calc, we were studying for the math midterm. I decide to look back at the very first unit, since that would re-jog my memory. Week 1 : Arithmetic and Geometric Series and Sequences. I believe the most beneficial way to help me prepare for the mid to was to look back and wright out the key things on one piece of paper.

MAKE SURE TO DO QUESTIONS FROM THE UNIT TOO!!! # Pre-Calc, Week 9

I learned in Pre Calc this week how to find the vertex of a quadratic equation that is in factored form. Here is how you find it: The first step is to find the x-intercepts or “zeros” of the equation. Once you’ve determined the zeros/ x-intercepts, you find the average of the zeros by adding them and dividing them by two. Once you find that, you plug it in as X in the equation in order to find Y. The x and y coordinates are the coordinates to your vertex.  