#trigonometric equation

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worn umbra
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Well consider that sin^2(x)=1-cos^2(x) then set X=cos(x) you’ll have a quadratic to solve

sly pendant
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this isn't really a "University" question...

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see if that makes sense to you

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if you have any questions

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lmk

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only the squared versions

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due to the idenity

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sin^2 + cos^2 = 1

sly pendant
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you'd rearrange

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yh exactly

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the trick to those questions is

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the trig function that isnt squared

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you wanna turn the squared one into the same one as it

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e.g.

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in this case

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cos wasnt squared

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so we turned the sin^2 into (1-cos^2)

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i skipped a couple steps

image.png
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but you get plus 5 from the top line

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and i multiplied the equation be -1

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yh lol

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"flip" hurts my soul 😭

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multiplied both sides by -1 what i did

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lol

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but its fine

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you're at school so its cool

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any other questions lmk

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otherwise you can close this

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also open it in the school section, because you'd get help faster in there

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because university helpers prolly wont spend time on those questions

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school helpers would

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cool

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solving the quadratic

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either you can factorise, or use the quadratic formula

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haha

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you should know how to use the quadratic formula

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basically

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you could factorise it

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do it by grouping

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you mustve been taught it

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its awkward to understand this without an example

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but its just a method

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not much to "understand"

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yh its just a method

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you can find millions of videos where you can learn it

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no

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because

Gn4PIaEd8bCvM44vtF2oWSioqKioqKioqKioqKCsn4PvThQe6eGyOAAAAAElFTkSuQmCC.png
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if you look at the graph

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cos's minimum is -1

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so when you do cos(x) = -5/2

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its not possible

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the graphs are better

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but you can

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no that value you get from your calc

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or memorised

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then the 2nd value is 2pi - pi/3

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cos(x) = 1/2 so x = arccos(1/2) = pi/3

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arccos might be written as cos^-1

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yh

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stick to what youve been taught

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anyways i gotta go do some work

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if you got other questions, definatly open a help in the school section

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much more poeple there to help