Expert: Paul Klarreich - 8/26/2009

Question
QUESTION: this is probaly really basic stuff...i just didn't take any notes on how to do these problems
can you explain to me how to do them too?

question 1, If an angle measures x(degrees) how can we represent its complement?

question 2, if a positive angle has measure x(degrees) between 0(degrees) and 60 (degrees) how  can we represent the first negative angele coterminal with it?

question 3, a pulley rotates through 75(degrees) in 1 min. How many rotations does the pulley make in an hour? i got 4500, since there are 60 minutes in an hour  so 60 * 75=4500

ANSWER: Questioner: dillon
Country: United States
Category: Advanced Math
Private: No
Subject: trig
Question: this is probaly really basic stuff...i just didn't take any notes on how to do these problems
can you explain to me how to do them too?

...............................................
question 1, If an angle measures x(degrees) how can we represent its complement?

Yes, it would have been good to have notes.  Without them, you just have to use your text, as in looking up the definition of complement.  (Well, at least you spelled it right.)

Complementary angles add up to 90 deg.

So the complement of x is 90 - x.

......................
question 2, if a positive angle has measure x(degrees) between 0(degrees) and 60 (degrees) how  can we represent the first negative angele coterminal with it?

Draw your diagram in standard position.  Then you will see that any angle coterminal with x(deg) has the form:

x + 360N, where N is any integer, positive or negative.

So to make 60 + 360N be the first (smallest) negative angle, make N = -1.

60 + 360(-1) = 60 - 360 = ...

...........................
question 3, a pulley rotates through 75(degrees) in 1 min. How many rotations does the pulley make in an hour? I got 4500, since there are 60 minutes in an hour  so 60 * 75=4500

You got 4500 whats?  4500 pounds?  4500 gallons?

OH! 4500 degrees!  Does that do it for you?


---------- FOLLOW-UP ----------

QUESTION: the directions are, in each figure, two similar triangles are present. Fine the value of each variable.

http://tinypic.com/r/nvdrpt/3
(picture of the triangle)

Answer
Questioner: dillon
Country: United States
Category: Advanced Math
Private: No
Subject: Similarity


QUESTION: the directions are, in each figure, two similar triangles are present. Fine the value of each variable.

http://tinypic.com/r/nvdrpt/3
(picture of the triangle)

Yes, you have similar triangles.  Name them. (See new pic, if I remember to send it.  Now you have:

ABC ~ ADE (in that order)  Then:
AB   AD
-- = ---  (I)
AC   AE

BC   DE
-- = --  (II)
AC   AE

x-2y    2x - y  << sum of x-2y and x+y
----- = ------ (I)
 5       15

x-5    15
---- = --  (II)
5     15

Now you have two equations in x,y to solve.  Go to it.

(P.S. Next time, send it through the site:

http://COLOSSALpic.com/r/nvdrpt/3

I hate tiny pictures.