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farah2318
why is 9sin(pi/3)= 9sqrt3/2 and 3tan(pi/4)=3 and 2 sec(pi/3)=4 and 5 cos(pi/4)= 5sqrt2 how would i figure these out?
try using the unit circle
how would i memorize all of that
Continuously draw the unit circle?
That's how it works for martial arts, biology and combat situations :|
do they have unit circle for tan and sec?
here's what it says in my book
|dw:1347081765068:dw| That suffice?
i would advice you to atleast remember these 3 values : \(sin (\pi/6)=0.5\) or sin 30 =0.5 \(sin (\pi/3)=\sqrt{3}/2\) or sin 60 =\(\sqrt{3}/2\) \(sin (\pi/4)=1/\sqrt{2}\) or sin 45 =\(1/\sqrt{2}\) then you can easily derive any ratio with angles 30,45,60 degrees, using standard formulas like sin x= cos (90-x) or cot x =cos x / sin x say cos 60 = sin (90-60)= sin 30 = 0.5 tan 45 = sin 45 / cos 45 = sin 45 / sin (90-45) = sin 45/sin 45 =1
from your question 2 sec \( \pi/3\)= 2/(cos\( \pi/3\) )= 2/(sin (\(\pi/2-\pi/3))\)=2/sin \( \pi/6\)=2/0.5=2*2=4 5 cos (pi/4)=5 sin (pi/2-pi/4)= 5 sin (pi/4) = 5/sqrt 2