Quandaries
and Queries
tracie
secondary
student
sin2x - sin x -12 = 0
sin 2x = -sin x
Hi Tracie,
Many algebra problems involve seeing a pattern. In your first problem I see
(something squared) - (the same something) - 12 = 0
that is
y2 - y - 12 = 0
Thus to do the problem let y = sinx an factor the resulting trinomial.
For the second problem you need to use the fact that
sin2x = 2 sinx
cosx
Penny