Week 6 PreCalc 11

This week we learned about solving quadratic equations, I learned three different ways to do this.

The one that I really like to use is this one.

I like this one because once I have my equation (4x^2+7x-1=0), then I just have to plug the numbers in. Whatever the coefficient is for x^2 then that is a, then whatever the coefficient is for x then that is b and c is the extra number.

Ex:

Week 5 PreCalc 11

This week we started factoring polynomial expressions. I learned how to take an equation like this 4x^2-7x+3 and factor it into two binomials. I did this by using a box method and using CDPEU which stands for Common, Difference, Pattern, Easy and Ugly.

ex:

I even learned how to take an even uglier expression and factor it.

Ex:

I did this by changing (7x-5) to a and I did this to both of the (7x-5)’s.

 

Week 4 PreCalc 11

This week in PreCalc we learned about solving radical equations. I learned how to take an ugly equation like this one 4=\sqrt{-2x} +3 and simplify it.

Ex:

To do so you have to state the restrictions of x(it’s mostly x>=0), then isolate x (if needed). Then you have to get rid of the square root by squaring it, then isolate x again. Then you have an answer. But you must check that it works by doing it again but by replacing x with what number you got and checking the restrictions.

Ex:

Week 3 PreCalc 11

This week in precalc we learned about simplifying radical expressions, I learned how to change mixed radicals into entire radicals and how to change entire radicals into mixed radicals.

To change a mixed radical(5\sqrt[4]{2}) into entire radicals($latex \sqrt[4]{1250}), this is what you need to do

To change it from a entire radical to a mixed radical, this is what you do.

Week 2 Pre Calc 11

This week I learned about Finite geometric series, I learned how to find t_n and I also learned how to find the sum of t_1 to t_n.

To find t_n you need t_1 and the common ratio.

So say I was trying to find t_(15), so t_1=4 and the common ratio is 3. This is what you would do.

Then to find the sum of all the 15 t’s, you would add t_1 + t_2 + t_3 +…etc. But the easier way to do it would be to do this.

 

My arithmetic sequence

t_1 = 3, t_2 = 10, t_3 = 17, t_4 = 24, t_5 = 31.

So 3, 10, 17, 24, 31…

t_{50}?   S_{50}?

what I would do first is find out what is t_{50}.

t_n=t_1+(n-1)d

t_{50}=3+49(7)

t_{50}=3+343

t_{50}=346

Now I need to find S_50.

S_n=\frac{n}{2}(t_1+t_{50})

S_{50}=\frac{50}{2}(3+346)

S_{50}=25(349)

S_{50}=8725

So t_{50}=346 and S_{50}=8725.

Week 1 Pre Calc 11

This short week we learned about sequences but more importantly we learned how to get whatever number from the sequence.

Basically if t_1 was 5, then t_2 was 10, and t_3 then with what we learned I could find out what was t_{45}.

this is how.

This is what I learned this past week!