Sunday, November 1, 2009

Amy's Reflection #11

ok ths week started chapter 9..i wonder if we're gonna go back and do chapter 8??..anyway im not really good at solving right angles so im not..dont want solve a problem wrong and confuse someone...but here are some things do understand:

Coversion:

Degrees to Radians is: degrees*pi/180
Radians to Degree is: radians*180/pi

Unit Circle:

90 degs. = (0,1) pi/2
180 degs. = (-1,0) pi
270 degs. = (0,-1) 3pi/2
360 degs. = (1,0) 2pi

sin=y/r
cos=x/r
tan=y/x
cot=x/y
sec=r/x
csc=r/y

SOHCAHTOA:

S = sin
O = opposite angle
H = hypotenuse
(sin = opposite/hypotenuse)

C = cos
A = adjacent angle
H = hypotenuse
(cos = adjacent/hypotenuse)

T = tan
O = opposite angle
A = adjacent angle
(tan = opposite/adjacent)

and i still need with the inverse stuff..if someone could help me with that..i'll really appreciate it..

1 comment:

  1. Inverses are pretty simple. They are used to find angle measures.

    to use sin inverse, you are looking for θ. you are given the side measure across from it and the hypotenuse.
    sinθ=(o/h)
    θ=sin^-1(a/c)

    to use cos inverse, still looking for θ, you are given side measure adjacent from it and the hypotenuse.
    cosθ=(a/h)
    θ=cos^-1(a/h)

    to use tan inverse, still looking for θ, you are given two side measures, the opposite and the adjacent.
    tanθ=(o/a)
    θ=tan^-1(o/a)

    you would plug in what θ is set equal to into the calculator to get the exact answer.

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