warm vortex
for these kinds of questions why do i need to use identities can i just rearrange for t like arcsin x= t and then substitute that into y ?to get it into cartesian ,why do i have to waste time with identities which will take me 5 tries to get "right "
warm vortex
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gusty valve
wdym
u could write it as y = sin(arcsin(x)+pi/4))
but then just expand and simplify ig
warm vortex
u could write it as y = sin(arcsin(x)+pi/4))
yeah
but the answer book uses identities
in fact any trig parametric equation uses identities
i dont get why
warm vortex
the book expands first?
yeah it use ddouble angle
warm vortex
then it does xcospi/4 + cos(arcsinx)sinpi/4 ?
gusty valve
oh fair
yeah i mean
u can sub in then expand if u want
but its just gonna be a messier eq
and
u kinda wanna eliminate trig functions
so thats what the pythag identity and expanding first allows u to do
with more ease
warm vortex
but have you ever encountered a situation where i would have to use identities to tackle the next part of the question
gusty valve
wdym next part
warm vortex
wdym next part
like as in for part b
cos sometimes when they make you do it a specific way
its so that you can be able to answer the second part of the question
gusty valve
nah i havent seen it like that
but it could be useful
if they ask u to find a point maybe
warm vortex
oh ok