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#1 2016-07-21 10:02:26
- dazzle1230
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- Registered: 2016-05-17
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Trigonometry
Help on these problems:
1)In triangle GHI, we have GH = HI = 25 and GI = 40. What is sin <GIH?
2)In triangle GHI, we have GH = HI = 25 and GI = 30. What is sin <GHI?
3)In triangle PQR, we have angle P = 90 degrees, QR = 15, and tan R = 5 cos Q. What is PQ?
Last edited by dazzle1230 (2016-07-21 10:21:49)
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#2 2016-07-21 16:14:50
- Monox D. I-Fly
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Re: Trigonometry
1) Draw a point J in the middle of GI, so IJ = 20. Using Pythagorean Theorem, HJ = 15. Sin GIH = HJ/HI = 15/25 = 3/5.
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#3 2016-07-22 01:16:31
- dazzle1230
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Re: Trigonometry
Thanks! How about the other two?
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#4 2016-07-22 01:52:57
- Bob
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Re: Trigonometry
Hi
For Q2, you can split the triangle down the middle to create a right angle.
For Q3, there is a right angled triangle, so call the opposite y, and the adjacent x. Form an equation from the given trig. equation and another from Pythagoras. and then solve for x and y.
Hope that works ... I am trying to do this on a kindle.
Bob
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob 
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#5 2016-07-22 02:12:09
- thickhead
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Re: Trigonometry
{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}
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#6 2016-07-22 05:46:18
- dazzle1230
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Re: Trigonometry
I also need help on these two:
1)In right triangle ABC, we have AB = 10, BC = 24, and angle ABC = 90 degrees. If M is on AC such that BM is a median of triangle ABC, then what is cos angle ABM?
2)How many values of x with
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#7 2016-07-22 17:50:24
- thickhead
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Re: Trigonometry
{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}
(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha
{Gods rejoice at those places where ladies are respected.}
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#8 2016-07-25 20:31:26
- Bob
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- Registered: 2010-06-20
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Re: Trigonometry
hi thickhead,
Post #5. Thanks for finishing that off. I was away from my laptop and trying to do this on a kindle without any pencil and paper. So I just posted what I could visualise. I knew a variable could be eliminated but hoped the poster would be able to do that step alone.
Turns out to be easier than I thought.
Bob
Children are not defined by school ...........The Fonz
You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you! …………….Bob
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