If sec^2(x) – 1 = sin(x) , which one of the following is a possible value for x?
how do you do this?
Thanks in advance. I don't get the sin,cosine rules so please help.! =)
The choices are
a) -
b)=
c) 0
d)
e)
thanks in advance!
If sec^2(x) – 1 = sin(x) , which one of the following is a possible value for x?
how do you do this?
Thanks in advance. I don't get the sin,cosine rules so please help.! =)
The choices are
a) -
b)=
c) 0
d)
e)
thanks in advance!
see, by inspection, 0 works.
note that the left hand side (which is actually ) is an even function, so if (a) and (b) don't work, (d) and (e) would give the same answer and hence not work either. (c) being 0 catches your eye though, and i would test that first, and what do you know, it worked!
doing this with the algebra would be a bit more complicated and time consuming. so just do the check. you have to check at most 3 values, which you can do pretty quickly if you memorized the trig values for the special angles.