• Want to level up your HSC prep on those harder Maths questions?
    Register now for the BoS Trials (7th October)!

Can someone help me with this circle geo Question (1 Viewer)

StudyMaster101

New Member
Joined
Mar 7, 2017
Messages
23
Gender
Female
HSC
2018
Yeah i'm a bit lost.

Its from cambridge yr 11 3u, Exercise 14H Q18

I think you use A=1/2 (absinC)

Screenshot (2).png

Thanks.
 

Drongoski

Well-Known Member
Joined
Feb 22, 2009
Messages
4,232
Gender
Male
HSC
N/A
Yeah i'm a bit lost.

Its from cambridge yr 11 3u, Exercise 14H Q18

I think you use A=1/2 (absinC)

View attachment 34563

Thanks.
Since PSQ is right-angled at S, PS = d cos @

Using: Area of triangle A = "(1/2)absinC" = (1/2) dcos@ x dcos @ x sin @ = (1/2)d2cos2@sin @

dA/d@ = 0.5d2cos@(1-3sin2@) = 0 when A is maximum.

Solving: sin2@ = 1/3

Substitute this into A = 0.5d2(1 - sin2@)sin@
you get A-max = the reqd result.
 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top