Trigonometry help

D.Roberts

D.Roberts

D.Roberts

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Hi all I know for some this will be easy..for me I was never good at maths.

I want to find out the formula used to find

b

I know a is 352
I know c is 1520

the answer is 1478 there about

this is the calculator I used

http://www.carbidedepot.com/formulas-trigright.asp

So whats the formula in simple terms please :P.

I have seen loads of YouTube vids but they all do it by knowing a length of one side and an angle.

Thanks
 
Is this SohCahToa? I have completely forgotten how to do anything like this and I used to be good at maths :(
 
You should post a diagram drawn on paint or explain it better.

You need 2 sides and at least an angle.

eg
a= 2m A=60 degrees
b= 3m
c= 4m

From there you could do sin rule or use SOHCAHTOA if it is a right angle triangle.

Edit: didn't read link
 
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If you have 2 lengths it's pythag not trig.

You say b is smaller than c, so c is the hypotenuse.

c2 = a2+b2

thus

b2 = c2-a2

comes to 1478.68
 
It's Pythagoras' Theorem. If it was Trigonometry it would involve angles.
(1st side)^2+(2nd side)^2=hypotenuse^2

Or a^2+b^2=c^2

As you already have the hypotenuse in this question you just rearrange to find the other side.
 
c^2-a^2=b^2

so, it's Pythagoras;

2310400-123904=2186496, then root 2186496=1478.680492871939, then round that to 1479, because the original numbers are 0 decimal place, this applies if the question asks for a appropriat edegree of accuracy.
 
Telescopi said:
As someone who sucks at maths I should state that not everybody can, it took me half-way through a physics a-level before I caught on. I'm still not sure why.
Click to expand...

You're right. I guess doing maths almost every day means I take it for granted! Although, I used to be absolutely rubbish at it. Didn't even get fractions until half way through secondary school :o But then it just clicked and I understood it. To me being good at maths is just about practice, just like any other skill.
 
Six7th said:
You're right. I guess doing maths almost every day means I take it for granted! Although, I used to be absolutely rubbish at it. Didn't even get fractions until half way through secondary school :o But then it just clicked and I understood it. To me being good at maths is just about practice, just like any other skill.
Click to expand...

Totally agree, still don't understand why simultaneous or quadratics work, I followed the formulas in maths / chem but don't know why. My brother looked at me like I was mad when I said that.

For some reason after an A1 physics that had lots of maths, going into A2 I just knew how to re-arrange formulas. Sucks as it went theoretical then.
 
Telescopi said:
Totally agree, still don't understand why simultaneous or quadratics work, I followed the formulas in maths / chem but don't know why. My brother looked at me like I was mad when I said that.
Click to expand...

ax^2+bx+c = 0

x^2 + (b/a)x + (c/a) = 0

[x + b/(2a)]^2 - (b^2)/(4a^2) + c/a = 0

[x + b/(2a)]^2 = (b^2)/(4a^2) - c/a

[x + b/(2a)]^2 = (b^2 - 4ac)/(4a^2)

x + b/(2a) = [+/- sqrt(b^2 - 4ac)]/(2a)

x = [-b +/- sqrt(b^2 - 4ac)]/(2a)

And that is why the quadratic formula works. It's just solving for x from the initial quadratic.
 
Morbius said:
ax^2+bx+c = 0

x^2 + (b/a)x + (c/a) = 0

[x + b/(2a)]^2 - (b^2)/(4a^2) + c/a = 0

[x + b/(2a)]^2 = (b^2)/(4a^2) - c/a

[x + b/(2a)]^2 = (b^2 - 4ac)/(4a^2)

x + b/(2a) = [+/- sqrt(b^2 - 4ac)]/(2a)

x = [-b +/- sqrt(b^2 - 4ac)]/(2a)

And that is why the quadratic formula works. It's just solving for x from the initial quadratic.
Click to expand...

What he said tbh :)
 
Telescopi said:
Totally agree, still don't understand why simultaneous or quadratics work, I followed the formulas in maths / chem but don't know why. My brother looked at me like I was mad when I said that.

For some reason after an A1 physics that had lots of maths, going into A2 I just knew how to re-arrange formulas. Sucks as it went theoretical then.
Click to expand...

Bleh, had a small rant about this in that A-level exam thread but it does really reflect how badly maths is taught. Shame really, as it's quite rewarding when not mindlessly following an algorithm to solve random equations all day. :p
 
Alex74 said:
Bleh, had a small rant about this in that A-level exam thread but it does really reflect how badly maths is taught. Shame really, as it's quite rewarding when not mindlessly following an algorithm to solve random equations all day. :p
Click to expand...

How do you think it should be taught then? I don't know you can have a rant about it without any solutions on how to solve this "problem".

Also talking about people to physics, I have not known anyone who has got a good grade in the first module who were not doing maths. Even though maths A level is not necessary for physics, it sure does how keep your maths skills up to scratch and like 70% involve maths.

Also I don't know about you but most of maths teaching up to year 9 was fairly interactive, we did not sit in classes all day solving problems. I remember when our teacher took us out onto the netball court and we had to find the value of PI.
 
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There are 3 female Red Indians sitting in a clearing. One of the women has 2 sons, and the other two women have 1 son each. The children are playing together. However, sitting on the sandy floor is uncomfortable, so two of the women (the two with 1 child each) have brought some animal skins to sit on. The third woman, however, has also brought lunch for the group, so has ridden a Hippo for the day, and she is currently sat atop it.

So how many children are each of the women responcible for? Easy.

"The sons of the Squaw on the Hippopotamus are equal to the son's of the Squaws on the other two Hydes"

:), I'll get me coat.
 
Skeeter said:
There are 3 female Red Indians sitting in a clearing. One of the women has 2 sons, and the other two women have 1 son each. The children are playing together. However, sitting on the sandy floor is uncomfortable, so two of the women (the two with 1 child each) have brought some animal skins to sit on. The third woman, however, has also brought lunch for the group, so has ridden a Hippo for the day, and she is currently sat atop it.

So how many children are each of the women responcible for? Easy.

"The sons of the Squaw on the Hippopotamus are equal to the son's of the Squaws on the other two Hydes"

:), I'll get me coat.
Click to expand...

:confused:
 
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