#year 13 trigonometry

24 messages · Page 1 of 1 (latest)

unique stump
#

help on part b, please <@&791435371564892232>

unique stump
#

<@&791435371564892232>

obtuse mica
#

Can you show me q1 please

#

part a i mean

#

@unique stump

obtuse mica
#

Let 4theta + 10degrees = 2x

#

if we look at what we are given in part a

#

we know that cosec2x + cot2x = cotx

#

hence cosec(4theta + 10) + cot(4theta + 10) = cot(2theta+5)

#

hence we can rewrite our equation as:

#

cot(2theta + 5 degrees) = sqrt(3)

#

cot = 1/tan(angle)

#

hence 1/tan(2theta + 5 degrees) = sqrt(3)

#

hence 1/sqrt(3) = tan(2theta+5)

#

arctan(1/sqrt3) = 30, 210 (although 210 is more than 180 we will still test to see if theta is less than 180)

#

our first equation will be 30 = 2theta + 5 hence theta = 12.5

#

our second equation will be (210 -5)/2 =102.5 = theta

#

if we want to test another value

#

just add 180 to 210 (period of tan)

#

390 = 2theta + 5

#

hence 385/2 = theta

#

sadly this is 192.5 which is out our range

#

no need to test any values less than 30 because they will be negative (-150) which will give us a negative theta which we dont want

rustic fjord
#

bro absolutely cooked