Alrighty so we finally finished the book this week. I thought it was a good book but it was just very different. Im glad that i had a chance to read it though because i learned a little about the dimensions and it helped me to think outside the box on things. Okay so im going to review some trig to refresh myself on some things.
**The tangent formulas:
Sum Formula for Tangent:
tan(alpha + beta) = tan alpha + tan beta/1-tan alpha (tan beta)
Difference Formula for Tangent:
tan(alpha - beta) = tan alpha - tan beta/1+tan alpha (tan beta)
EXAMPLES:1)
Find the exact value of tan15 degrees+tan30 degrees/1-tan15 degrees
(tan30 degrees)
= tan(15 degrees + 30 degrees)
= tan(45 degrees)
= 1
Keep in mind that for these answers you have to know the trig chart!!
2)Find tan(alpha+beta)
tan alpha=2 tan beta=1
tan(alpha+beta) = tan alpha+tan beta/1-tan alpha(tan beta)
= 2+1/1-(2)(1)
= 3/-1
= -3
I look forward to watching the movie on flatland tomorrow so i can clear up some things that confuse me in the book. I could use some help with sigma notation!!
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Sigma has three parts
ReplyDeleteA top number
A middle number
A bottom number
Top is called limit of summation
Middle is called the summand
Bottom is called index
Top is the address of the last number in given series
Middle is the result of the tn formula
Bottom is what number you start counting at
If the equation is arithmetic then the bottom number will be 1
If the equation is geometric then the bottom number will be 0
When asked to evaluate for a sigma problem you plug in the numbers including and between the bottom and the top numbers
So if the bottom number is one and the top number is five then you would plug in 1,2,3,4,5 for the variable of the middle equation and add the results of each plug in togethe3r to get the final answer
When asked to express then you draw the sigma sign and fill in the top middle and bottom parts