Here are some more trig facts
Unit Circle:
90 degs. = (0,1) pi/2
180 degs. = (-1,0) pi2
70 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)
*the hypotenuse is opposite the right angle.
*A= 1/2 bh*
*To find the area of a non right triangle use this formula:
*A= 1/2 (leg)(leg)SIN(angle b/w)
*When you have a non right triangle that has pairs, use the law of sines:
Sin A/a = Sin B/b= Sin C/c
*All you are doing is setting up a proportion.
**Remember to solve for an angle, you have to take the inverse.
*To solve a triangle with no angles, use the Law of Cosines:
(opp leg)^2= (adj leg)^2 + (other adj leg)^2 -2(adj leg)(adj leg) Cos(angle b/w)
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Example: f(x)= 2x^3 + 3x^2 - 8 + 3
ReplyDeleteStep 1: find all possible roots..
p: factors of 3: 1, -1, 3, -3
q: factors of 2: 1, -1, 2, -2
*p is the leading constant term & q is the leading coefficient
possible roots are (p/q): 1, -1, 1/2, -1/2, 3, -3, 3/2, -3/2
Step 2: now you can plug all of the possible roots in your calculator to find the roots that work
the zero will be: 1, 1/2, -3
Step 3: use synthetic division to factor all of the roots that work
you should get: (x - 1) (2x^2 + 5x + 3)
Step 4: slove further
(this can be factored...)
= (x - 1) (2x^2 + 5x + 3)
= (x - 1) (2x - 1) (x + 3)
(set x = 0 )
x = 1, 1/2, -3