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Week 10 in PreCalc 11

As our math midterm is getting near, this week has been a review week which has been a great refresher for my memory. It was good and bad to know that I’ve forgotten a lot of things. But it’s a good thing to reflect to when studying!

Not much was learned, but rather a lot of refreshers. Here are some of them:

I wouldn’t go into much details about them all as I’ve posted them already in my edublog, but I would do some examples. Here are the links to the blog posts:

Absolute Values:

• how far away a number from zero is in a number line.
• $\sqrt{x}^2$
• The answer will always be positive inside the absolute value sign ” | | “
• Can act like a parenthesis.

Examples:

| 5 – 7 |

= | -2 |

= 2

-|-4|

= – | 4

= -4

Arithmetic Sequence:

• A sequence of numbers that are added or subtracted by the same value.
• Addition of a number sequence. E.g. 1 + 2 + 3 + 4 + 5 + 6….
• $S_n = \frac{n}{2}(a + t_n)$
• $S_n = \frac{n}{2}(2a + (n-1)d)$
• n = the number/amount of terms you’re calculating
• a = the first term
• tn = last term
• d = common difference

Example:

2 + 5 + 8 + 11…

n = 20

a = 2

Since we don’t have tn, we’ll be using the second formula.

$S_n = \frac{n}{2}(2a + (n-1)d)$ $S_{20} = \frac{20}{2}(2(2) + (20-1)3)$ $S_{20} = 10 (4 + 57)$ $S_{20} = 10 (61)$ $S_{20} =610$

• Simplify if possible.
• $\sqrt[n]{x}$
• n is index, and x is radicand.

Examples:

$\sqrt{3} + 2\sqrt{3} = 3\sqrt{3}$

$4\sqrt[4]{5} - \sqrt{5}$
$4\sqrt[4]{5} - \sqrt{5}$