MATHS FORMULAS?! (1 Viewer)

[nirukk]

I am having problems with maths formulas. 2 units are all right, but the trig identities I keep forgetting after like 2 weeks or so after doing the questions.
Does anyone have any formula sheets or somewhat like that ? I am gonna buy large papers and write the formulas in coloured pen and then stick it on my wall. So every time I wake up I can look on them.

 

[SpiralFlex]

If I throw an apple at you while you are blindfolded. Can you see which direction it comes from? - Nope.

But if you take your blindfold off you may be you can see where the apple comes from.

Point is. perhaps you should understand where these formulae come from. This may help you make get rid of the feeling of a barrage of formulae being thrown at you.

+ Practice

 

[Timske]

yeah i do but its on paper :| ill write it up lol

Trigonometric Ratios
tan x = sin x/cos x
cosec x = 1 / sin x
sec x = 1/cos x
cot x = 1/tan x = cos x / sin x

Exact Trigonometric Ratios:
sin45 = 1/root(2)
cos45 = 1/root(2)
tan45 = 1
sin30 = 1/2
cos30 = root(3)/2
tan30 = 1/root(3)
sin60 = root(3)/2
cos60 = 1/2
tan60 = root(3)

Trigonometric Identities
sin^2 x + cos^2 x = 1
1 + tan^2 x = sec^2 x
1 + cot^2 x = cosec^2 x

Sum and Differences of Angles
sin (A+B) = sinAcosB + cosAsinB
sin (A-B) = sinAcosB - cosAsinB
cos (A+B) = cosAcosB - sinAsinB
cos (A-B) = cosAcosB + sinAsinB
tan (A+B) = (tanA + tanB) / (1 - tanAtanB)
tan (A-B) = (tanA - tanB) / (1 +tanAtanB)

Double Angle Formulae
sin2x = 2sinxcosx
cos2x = cos^x - sin^2x
= 2cos^2x - 1
= 1 - 2sin^2x
tan2x = 2tanx/(1 - tan^2x)

lbut yeah u should keep to what spiral says dont try to memorise

 

[deswa1]

Just a tip of what's helped me is don't remember all of them. For example, I just remember that sin^2x+cos^2x=1, then if I want to know the other two, I can just divide through by either sin^2x or cos^2x.

 

[funnytomato]

If I throw an apple at you while you are blindfolded. Can you see which direction it comes from? - Nope.

But if you take your blindfold off you may be you can see where the apple comes from.

Point is. perhaps you should understand where these formulae come from. This may help you make get rid of the feeling of a barrage of formulae being thrown at you.

+ Practice

+1

derive them, practice, derive them again if you forget ...

 

[Carrotsticks]

Unit circle is the way to go.

 

[SpiralFlex]

If I can't remember formulae, I sing this song.