Question 655709: sin(3 pie/4) without using a calculator
sin of alpha= y/r
so far:
I drew a 45-45-90 triangle
the book uses y=1
x=1 and somehow r= square root of 2
where do I go from here and how to I get the values of x,y, and r in these kinds of problems?
thanks for your help.
my name is Corinna.
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! sin(3 pie/4) without using a calculator
sin of alpha= y/r
so far:
I drew a 45-45-90 triangle
the book uses y=1
x=1 and somehow r= square root of 2
where do I go from here and how to I get the values of x,y, and r in these kinds of problems?
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3pi/4 = 135 degs, if that's easier
(PS, it's pi, the Greek letter, not pie, the dessert)
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I drew a 45-45-90 triangle
the book uses y=1
x=1 and somehow r= square root of 2
-------
For a right triangle with x & y = 1, use Pythagoras to find r, the hypotenuse.
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Then at 135 degs, y is +1 and x is -1
= 
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