Friday, March 18, 2011

tan sin and cos examples, problems

How to punch in tan, cos, sin and the angle:
Press either the angle or the ratio first than the other and the answer comes up usually in a very small number like,  tan20=0.36397023426620236135104788277683

A hiker(b) is looking down at city at a 76 degree angle, what is the distance of the cities length (opposite). say we know the adjacent (1223 ft), and we need to know the length of opposite so the equation for opposite and adjacent is tangent (tan=o/a) so then all we do is tan 76 and multiply that by 1223 which is the adjacent.

Then we get 4905.2 ft as the opposite. Which is the length of the city.  
 (forget 76 as angle for b)Say we dont know angle c but we know each side of the triangle: (ac=10, ab=15, bc=18).  Say that we need to find angle c.  So we can use two of the three terms, tan or sin.  We will use tan so that is the adjacent and the oppoisite of the angle, ac=10 and ab=15.  So the inverse of tan to cancel tan. So the equation to solve it tan-1=15/10 which 56.3.
Now say we dont know the hypotenuse but we have the adjacent side to c, adjacent(10) over hypotanuse would be cos.  The equation would be cos56.3=10/h so to solve we would it be 18.

Thursday, March 17, 2011

right triangles and sine, cosine and tangent

 The ratio of the opposite side of a right triangle to the hypotenuse the sine and give it the symbol
sin = o / h
The ratio of the adjacent side of a right triangle to the hypotenuse is called the cosine and given the symbol
cos = a / h
Finally, the ratio of the opposite side to the adjacent side is called the tangent and given the symbol
tan = o / a
If we knew at least one of each part of the ratio we could find the answer.

tang wavelength is the green

green line is y=tan(x), black line is y=sin(x), red isy=cos(x)

Wednesday, March 16, 2011

graphing sin

blue and pink are from original comparing to black(y=7sin(x) and red(y=sin(7x).

Monday, March 7, 2011

scale model

the dime on the left is the original for my scale and the one on the left is my model which is 3 mm to 1 inch
a dime is 18 mm in diameter and 1 mm thick.  the model is 6 inches in diameter.   

Tuesday, March 1, 2011

second floor

 here is the second floor to the mansion. above the 
pantry in the first floor that was cut out but is on the bottom of this picture is a bedroom.

First floor

  This is a scale model of a fictional mansion.  The scale is two feet for every section of the dots. sorry the writing on the scale is blurry, so ill tell were each room is on the 1st floor of the mansion:  The top left there is a room behind a hallway, in front of the hallway there is the living room with the bathroom on the left of the living room. in front of the living room there is an office space and on the right side next to the living room there is a walkway and the kitchen, in front of the kitchen there is the stairs to the second floor and the entrance. To the right of the kitchen there is a pantry, but it was cut out when i took the picture. behind the kitchen is the second living area.

Thursday, February 17, 2011

classroom scale, 2ft to one square on paper, 1cm

The bigger desks were 2' 6''x4'6''. the smaller desks were 2'x 3' 5''. the whole room is 31'x 29'. The counter in front of the room is 3'x8', each door is 3'8''.

Friday, January 28, 2011

Congruence with proofs

2nd semester 5/6 class had talked about congruence with triangles. Congruence included statemnets with proofs. These prooves are statements that tell wether or not the triangles are equal in certain measurements. The final proofs concluded the triangles congruency. These statments are Side,side,side(sss): proofing all sides are the same. side,angle,side(sas):proofing a side then an angle then side. Angle,angle,side(aas,saa): proofing angle,angle, then a side. Angle,side,angle(asa): An angle then a side then a angle. Last Hypotynuse leg(HL): if the triangles are right the longest side(Hypotynuse).