help how is it A (1 Viewer)

anonymoushehe

Active Member
Joined
Apr 15, 2022
Messages
193
Location
Newcastle, NSW
Gender
Male
HSC
2025
Screenshot 2025-04-17 at 8.29.01 pm.png
I got B?? I solved it by working out the domains and ranges for each separate function and then added the max and min values of each interval?
 

Hehehe22

Active Member
Joined
Sep 17, 2024
Messages
327
Gender
Female
HSC
2025
You can't do that because the min and max y values aren't at the same x value. You can see this if you graph it
1744887852096.png
 

zzz5428

Member
Joined
Sep 25, 2024
Messages
62
Gender
Male
HSC
2024
A more reliable way to do this is using the identity: arcsinx + arccosx = pi/2. This is pretty well known and can easily be proved. The method mentioned above is unreasonable as you cannot assume that applies to all x in the domain even though it does.
 

anonymoushehe

Active Member
Joined
Apr 15, 2022
Messages
193
Location
Newcastle, NSW
Gender
Male
HSC
2025
A more reliable way to do this is using the identity: arcsinx + arccosx = pi/2. This is pretty well known and can easily be proved. The method mentioned above is unreasonable as you cannot assume that applies to all x in the domain even though it does.
OHHHH thats also very smart thank youu
 

NotBamboo

Well-Known Member
Joined
Apr 2, 2025
Messages
214
Location
Gender
Male
HSC
2026
I legit just chucked the max and min of the domain into the calculator and sees if theres a math error (C and D) or an answer (got 180 so 1 radian)
this won't work for other questions but we haven't even learnt inverse sin graphs yet
 

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

Top