• Trigonometry Help
    19 replies, posted
I have a homework due tomorrow, I'm having problems using the Sin, Cos, Tan to find the length of a hypotenuse. This is what the problem looks like: [IMG]http://img197.imageshack.us/img197/5541/mathproblem.jpg[/IMG] X is the hypotenuse, 12 degrees on a angle and 36 yards/units on the opposite side. This is a angle of elevation.
Sin(12)=.2079 according to my calculator. Since sin=opposite/hypotenuse, you can set up the equation like so: .2079=36/x, where x is the hypotenuse.
:psyduck:
Alright, let me re-explain this. To do this, you need to remember the mnemonic SOH-CAH-TOA: Sine is opposite side over hypotenuse, cosine is adjacent side over hypotenuse, and tangent is opposite side over adjacent side. By opposite and adjacent, I mean relative to the angle. In OP's example, the side with length 36 units is the opposite side. With this knowledge, we can find the hypotenuse if we've been given at least one side and one angle. In the OP's example, we've been given the opposite side and are searching for the hypotenuse, so it's a job for the sine function. Use a calculator to find sin(12). As I stated above, it comes to .2079. Using the above definition for sine (sine=opposite/hypotenuse), we can set up a simple equation. Let x = length of hypotenuse. sinΘ=opp/hyp sin(12)=36/x .2079=36/x .2079x=36 x=173.16 Any more questions? I'll be glad to answer. [editline]01:30AM[/editline] FYI, I have about 5 people that I get paid to tutor in math. :c00l:
[QUOTE=PrismatexV8;20824772]Sin(12)=.2079 according to my calculator. Since sin=opposite/hypotenuse, you can set up the equation like so: .2079=36/x, where x is the hypotenuse.[/QUOTE] Thanks! Ill try to solve the equation like that. [editline]10:34PM[/editline] [QUOTE=PrismatexV8;20824929]Alright, let me re-explain this. To do this, you need to remember the mnemonic SOH-CAH-TOA: Sine is opposite side over hypotenuse, cosine is adjacent side over hypotenuse, and tangent is opposite side over adjacent side. By opposite and adjacent, I mean relative to the angle. In OP's example, the side with length 36 units is the opposite side. With this knowledge, we can find the hypotenuse if we've been given at least one side and one angle. In the OP's example, we've been given the opposite side and are searching for the hypotenuse, so it's a job for the sine function. Use a calculator to find sin(12). As I stated above, it comes to .2079. Using the above definition for sine (sine=opposite/hypotenuse), we can set up a simple equation. Let x = length of hypotenuse. sin&#920;=opp/hyp sin(12)=36/x .2079=36/x [B][I][U].2079x=36[/U][/I][/B]<---------------- x=173.16 Any more questions? I'll be glad to answer. [editline]01:30AM[/editline] FYI, I have about 5 people that I get paid to tutor in math. :c00l:[/QUOTE] I got to that part and I couldn't isolate x in order to have it equal to 176, how would you do that
.2079x=36 Multiply each side by .2079 (with decimals, multiplying produces a more realistic number). You do that and you get X=7.4844 Or, the way I do it, 36 divided by the square root of three times 2.
If you are already having trouble at this stage of trigonometry, God help you. Just wait until you get onto unit circles involving radians, and graphing trigonometric expressions.
[QUOTE=icypenguin;20830569]If you are already having trouble at this stage of trigonometry, God help you. Just wait until you get onto unit circles involving radians, and graphing trigonometric expressions.[/QUOTE] Oh come now, they aren't that difficult, i'm sure if he tries more questions then he'll do just fine.
[QUOTE=AmericanInfantry;20830350].2079x=36 Multiply each side by .2079 (with decimals, multiplying produces a more realistic number). You do that and you get X=7.4844 Or, the way I do it, 36 divided by the square root of three times 2.[/QUOTE] Try dividing.
[QUOTE=AmericanInfantry;20830350].2079x=36 Multiply each side by .2079 (with decimals, multiplying produces a more realistic number). You do that and you get X=7.4844 Or, the way I do it, 36 divided by the square root of three times 2.[/QUOTE] Except that only works with a 30-60-90 triangle. [editline]04:46PM[/editline] [QUOTE=AmericanInfantry;20830350].2079x=36 Multiply each side by .2079 (with decimals, multiplying produces a more realistic number). You do that and you get X=7.4844 Or, the way I do it, 36 divided by the square root of three times 2.[/QUOTE] x=7.48 doesn't even work. It's less than one of the legs, so it doesn't exactly check out. Your math is faulty as well. ka=b and you multiply by k? You want to get rid of k, so you divide by k. You only multiply by k if a is being divided by something, like a/k=b. :colbert:
This is soo easy. 36u/x=sin12 36u=x*sin12 36u/sin12=x
[QUOTE=Un.Hxx.Aé;20833458]This is soo easy. 36u/x=sin12 36u=x*sin12 36u/sin12=x[/QUOTE] Which is why I showed that in the first reply 15 hours ago: [QUOTE=PrismatexV8;20824772]Sin(12)=.2079 according to my calculator. Since sin=opposite/hypotenuse, you can set up the equation like so: .2079=36/x, where x is the hypotenuse.[/QUOTE] RTFT
173.15u
[QUOTE=Un.Hxx.Aé;20833546]173.15u[/QUOTE] Again, 15 hours ago. [QUOTE=PrismatexV8;20824929]Alright, let me re-explain this. To do this, you need to remember the mnemonic SOH-CAH-TOA: Sine is opposite side over hypotenuse, cosine is adjacent side over hypotenuse, and tangent is opposite side over adjacent side. By opposite and adjacent, I mean relative to the angle. In OP's example, the side with length 36 units is the opposite side. With this knowledge, we can find the hypotenuse if we've been given at least one side and one angle. In the OP's example, we've been given the opposite side and are searching for the hypotenuse, so it's a job for the sine function. Use a calculator to find sin(12). As I stated above, it comes to .2079. Using the above definition for sine (sine=opposite/hypotenuse), we can set up a simple equation. Let x = length of hypotenuse. sin&#920;=opp/hyp sin(12)=36/x .2079=36/x .2079x=36 x=173.16 Any more questions? I'll be glad to answer.[/QUOTE] RTFT
Nuh-uh, you didn't solve it for him. No hard feelings ok?
[QUOTE=Un.Hxx.Aé;20833670]Nuh-uh, you didn't solve it for him. No hard feelings ok?[/QUOTE] [QUOTE=PrismatexV8;20824929] sin&#920;=opp/hyp sin(12)=36/x .2079=36/x .2079x=36 [highlight]x=173.16[/highlight][/QUOTE] :smug:
Ok I got the whole Concept!!! thank you very much everyone who tried! :q:
SinA/a = SinB/b Sin12/36 = Sin90/x algebra from then on. might be simpler than above
Just remember SohCahToa Sin = Opposite/hypotenuse Cos = Adjacent/hypotenuse Tan = opposite/adjacent
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