#How can I do “cast diagrams” for further maths.

1 messages · Page 1 of 1 (latest)

tall flume
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How can I learn this

brazen prawnBOT
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indigo socket
tall flume
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Yeah I think

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I’m doing further maths gcse and I watched a corbet maths vid on it but I still don’t get it

indigo socket
marble surge
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think about how cos(x) represents the horizontal distance on the unit circle made by the right angle triangle

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lemme draw a diagram

indigo socket
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i wouldn't necessarily use cast here, tbf.

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just know where arccos and arcsin are defined and its relatively simple to

marble surge
indigo socket
marble surge
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just think about

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in which regions of the circle

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are sin(theta) going to be positive

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well obviously it's the top two because the right angle triangle "goes up"

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and cos(theta) is going to be positive in the right two quadrants because the triangle is to the right so it's a positive distance

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basically, as theta goes around the circle, the cast diagram tells us if sin(theta) or cos(theta) will be positive or negative

marble surge
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like most students will just know of arcsin as the opposite of sin

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as in to find the angle

indigo socket
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thats nto necessarily a good foundation, as the range of arcsin is $[-\frac{\pi}{2},\frac{\pi}{2}]$

spiral swallowBOT
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dark matter

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marble surge
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also we havent been taught radians lmao

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but yeah i hate how maths is taught in school

indigo socket
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what.

marble surge
indigo socket
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im 16.

marble surge
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yea radians are only introduces in the year aftert

marble surge
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it's not a very interesting course i mean

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you learn the power rule of differentiating

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no integrals

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only trig identities are the sin/cos = tan and sin^2x + cos^2x = 1

indigo socket
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oh

marble surge
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not taught cot sec or csc

indigo socket
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wow

marble surge
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oh the worst part

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you learn matrices but not in the context of linear algebra at all so it just seems entirely unintuitive

indigo socket
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whaaaaaaat

strong lotusBOT
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@tall flume

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grave crystal
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are you doing aqa or edexcel

marble surge
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Literally only new topic was formula of a circle and matrices everything else is pretty much the same

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Oh and binomial expansion w integer powers > 0

grave crystal