# Week 19 – Top 5 Things I learned in precalculus 11

This year in Precalculus 11 I learned so many things and different things in each unit. Some of the units were a little bit hard and some of the units were easy.  Here are the top things I’ve learned in precalculus 11.

1. The first thing in the top five is multiplying and dividing rational expression. It’s used for simplifying products and quotients of rational expression. Here is an example:

2. The second thing in the top five is the arithmetic series. It’s used to determine the sum of n term of an arithmetic series, then solve related problems. Here is an example:

3. The third thing in the top five is using special triangles. It’s used to explore the condition for which given information is sufficient to construct a unique triangle. For example:

4. The fourth thing in the top five is solving systems of equations algebraically. Use algebraic strategies to solve linear quadratic system and quadratic-quadratic system. For example:

5. The fifth thing in the top five is multiplying and dividing radical expressions. It’s used to simplify products and quotients of radical expression. Here is an example:

# Week 18 – precalculus 11

This week in precalculus 11 I learned about cosine law. Cosine Law is to solve triangles that are not right triangles. We should know that we use the sine law when we have given two angles and one side, or two sides and a non-included angle, and we use the cosine law when we are given three sides, or two sides and the included angle.

The formula for cosine law is:

${a^2}$ = ${b^2}$ + ${c^2}$ – 2bc cosA

Here is an example:

# Week 17 – precalculus 11

This week in precalculus 11 I learned about Sine Law.  I learned about trigonometry in grade 10 but this year we expand it a little bit more. Sine Law is to solve problems in triangles that are not right triangles. The formula for sine Law is:

Missing side: $\frac{a}{sin A}$ = $\frac{b}{sin B}$ = $\frac{c}{sin C}$

And

missing angle:$\frac{sin A}{a}$ = $\frac{sin B}{b}$ = $\frac{sin C}{c}$

Here is an example:

# Week 16 – precalculus 11

This week in pre-calculus 11 I learned about rational equations. Rational equations have at least one fraction whose numerator and denominator are variable. Two ways of solving rational equation; one way is cross to multiply when there are just 2 fractions and with an equal sign in between, the other way is to multiply all terms by denominators when there are more than 2 fractions.

Here is an Example:

# Week 15 – precalculus 11

This week in pre-calculus 11, I learned about multiplying and dividing rational expression. Actually, I learned a basic way of multiplying and dividing rational expression in grade nine and ten, but this year it got a little bit complicated and we expanded more to it.

Here is an example:

# Week 14 – precalculus 11

This week in precalculus 11 I learned about Rational Expression. It was an easy and short lesson.

Here is an example:

# Week 13 – precalculus 11

This week in precalculus 11 I learned about solving absolute value algebraically.

Here is an example:

# Week 12 – precalculus 11

This week in precalculus 11, I learned about solving systems of equation algebraically. Here is an example:

# Week 11 – precalculus 11

this week in precalculus 11 I learned about solving quadratic inequalities in one variable.

Here is an example:

# Week 10- precalculus 11

For the midterm, I reviewed everything that I have learned till now. One thing that I was reviewing that was not blogged about previously is a common difference. Here is an example: