How do I solve for x(Trigonometry question ) | Mathematics | Page 1

vernal beacon Mar 20, 2025, 10:58 AM

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No clue how to solve it

lethal roostBOT Mar 20, 2025, 10:58 AM

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vernal beacon No clue how to solve it

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fresh cloak Mar 20, 2025, 11:23 AM

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vernal beacon No clue how to solve it

,rccw

twin depotBOT Mar 20, 2025, 11:23 AM

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fresh cloak Mar 20, 2025, 11:24 AM

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whats A1 and A2?

vernal beacon Mar 20, 2025, 11:29 AM

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i think its area 1 and area 2

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I think like 1 triangle is a1 and another is a2

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Not sure my teacher didnt go through a question like this

fresh cloak Mar 20, 2025, 11:36 AM

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hm I wanted to assume the triangle to be an equilateral but I calculated the opposite angle of 30 and it comes as 29.5

fresh cloak Mar 20, 2025, 11:36 AM

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vernal beacon Not sure my teacher didnt go through a question like this

do you know cos rule and sine rules?

vernal beacon Mar 20, 2025, 11:36 AM

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yes

fresh cloak Mar 20, 2025, 11:37 AM

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Can u try finding this using cos rule?

fresh cloak Mar 20, 2025, 11:38 AM

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twin depot

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Take the triangle as one

vernal beacon Mar 20, 2025, 11:39 AM

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OK

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y^2=15^2+30^2-2(15)(30)cos(70

fresh cloak Mar 20, 2025, 11:43 AM

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fresh cloak

fresh cloak Mar 20, 2025, 11:43 AM

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vernal beacon y^2=15^2+30^2-2(15)(30)cos(70

And then afterwards use that y value

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And use the sine rule to find the green angle

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Tell me the value

vernal beacon Mar 20, 2025, 11:43 AM

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Ok

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of the angle or y

fresh cloak Mar 20, 2025, 11:44 AM

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angle

vernal beacon Mar 20, 2025, 11:46 AM

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nearest min?

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10 degree 20 min for nearest minute

fresh cloak Mar 20, 2025, 11:47 AM

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vernal beacon nearest min?

Wdym nearest minute?

vernal beacon Mar 20, 2025, 11:47 AM

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for the angle

fresh cloak Mar 20, 2025, 11:48 AM

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Round the angle off to one 1 decimal place

fresh cloak Mar 20, 2025, 11:48 AM

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vernal beacon for the angle

Why is there minutes?

vernal beacon Mar 20, 2025, 11:49 AM

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10.3 1dp

fresh cloak Mar 20, 2025, 11:50 AM

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Show me your full working

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For y and the angle both

vernal beacon Mar 20, 2025, 11:50 AM

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is it wrong

fresh cloak Mar 20, 2025, 11:50 AM

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Yes

vernal beacon Mar 20, 2025, 11:51 AM

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Brb

fresh cloak Mar 20, 2025, 12:00 PM

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vernal beacon

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Why did you write 20 here?

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Also your sin inverse has to account for the 28.58 as well

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first find (sin70*15)/28.58

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then take the sin inverse of that value

vernal beacon Mar 20, 2025, 12:21 PM

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oops

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wrong number

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do i use the number i got from y like all the numbers after decimal place or just 2 dp

fresh cloak Mar 20, 2025, 12:22 PM

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vernal beacon do i use the number i got from y like all the numbers after decimal place or jus...

yea you can take it as 2dp

vernal beacon Mar 20, 2025, 12:22 PM

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Ok

fresh cloak Mar 20, 2025, 12:23 PM

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and tell me what value u get for the angle

vernal beacon Mar 20, 2025, 12:23 PM

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how many dp?

fresh cloak Mar 20, 2025, 12:23 PM

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2

vernal beacon Mar 20, 2025, 12:24 PM

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29.54

fresh cloak Mar 20, 2025, 12:25 PM

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okay nice

fresh cloak Mar 20, 2025, 12:25 PM

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fresh cloak

now find the remaining angle

vernal beacon Mar 20, 2025, 12:25 PM

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Ok

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80.46

brave jetty Mar 20, 2025, 12:25 PM

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vernal beacon No clue how to solve it

Lets mark AB = 30cm
AC=15cm
AD = x

Find BC using cosine rule
Then find angles B and C using sine rule.
Then find x using sine rule

vernal beacon Mar 20, 2025, 12:28 PM

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for x do i use the triangle on the right? the one with Ab as 30cm

fresh cloak Mar 20, 2025, 12:30 PM

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This angle I mean

fresh cloak Mar 20, 2025, 12:30 PM

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fresh cloak

vernal beacon Mar 20, 2025, 12:30 PM

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oh

fresh cloak Mar 20, 2025, 12:31 PM

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fresh cloak

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And then u use sine rule using the 2 angles u found to find x

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Try it out

vernal beacon Mar 20, 2025, 12:32 PM

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Ok

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17.16?

fresh cloak Mar 20, 2025, 12:37 PM

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vernal beacon 17.16?

its 17.15 actually

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I think you might hv made a rounding off error in ur prev workings but it shld be fine

vernal beacon Mar 20, 2025, 12:39 PM

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Was it from the y?

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I rounded for y to 28.59

fresh cloak Mar 20, 2025, 12:40 PM

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no thats correct

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what does your calculator show?

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like the full ans

vernal beacon Mar 20, 2025, 12:40 PM

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of which part?

fresh cloak Mar 20, 2025, 12:40 PM

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of x

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the final ans

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mine shows 17.14508..

vernal beacon Mar 20, 2025, 12:41 PM

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17.15918655...

fresh cloak Mar 20, 2025, 12:42 PM

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hmm for x did you take it as 30/sin120.5 * sin29.5 ?

vernal beacon Mar 20, 2025, 12:43 PM

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i did 30/sin120.46 * sin29.54

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fresh cloak Mar 20, 2025, 12:44 PM

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ahh okay then thats correct I only took mine for 1dp

vernal beacon Mar 20, 2025, 12:44 PM

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ohh

fresh cloak Mar 20, 2025, 12:44 PM

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vernal beacon

nice

vernal beacon Mar 20, 2025, 12:44 PM

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all good

fresh cloak Mar 20, 2025, 12:44 PM

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yep

vernal beacon Mar 20, 2025, 12:44 PM

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thank you for the help

fresh cloak Mar 20, 2025, 12:44 PM

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nws

vernal beacon Mar 20, 2025, 12:44 PM

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happy

fresh cloak Mar 20, 2025, 12:45 PM

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close the thread if ur qs are answered

vernal beacon Mar 20, 2025, 12:45 PM

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Yep

#How do I solve for x(Trigonometry question )